How to research and find an illegitimate ancestor is challenging for the most seasoned genealogy researcher. Explore these tips and types of records for clues to your ancestor's parents.
Female Ancestors,  Genealogy Research,  How To Trace Your Family Tree

How To Research Your Illegitimate Ancestors

Researching illegitimate ancestors is challenging for genealogy researchers. Explore these tips and resources for clues to your ancestor’s parents.

Are you researching an ancestor born out of wedlock?

Do you suspect your ancestor was illegitimate?

If your answer to either question is “Yes”, then you have encountered the difficulties in researching an illegitimate ancestor.

Is it possible to determine the parents of an illegitimate child? 


Sometimes you know one parent (typically the mother, but not always).

Sometimes you only find circumstantial evidence pointing to the potential parents. The challenge is finding which records hold the clues you need.

Black and white version of a tree with faded white box with red letters reading How to Research your Illegitimate Ancestors
Pin for Future Reference!

What Types of Genealogy Records Should You Pursue When Researching an Illegitimate Ancestor?

Before we get into the records and resources let’s talk about  the terminology you might encounter in your search. Some of the terms are no longer in use today or may be found offensive in today’s culture. Remember as you read the documents and as we discuss resources, the terminology used is of that time period and not necessarily today’s use of the word.

Common vocabulary encountered referring to a child when researching illegitimate ancestors:

  • Base-born
  • Bastard
  • Born out of wedlock
  • Natural
  • Reputed  – as in “reputed son of ” 
  • Imputed – as in the “imputed son of” indicates the mother was accusing the man of being the father
  • Ignotus  – Latin term for “unknown”; may be seen in church records

Oral History

Often oral history provides the best clues to identifying if your ancestor is illegitimate and/or who the parents are.

One of the interesting things I found in pursuing illegitimate ancestors, is what was common knowledge in one generation is not necessarily passed down to the next generation or two.  This makes sense.  Illegitimacy was (and still can be) a very sensitive topic and not one generally talked about openly.

Explore your family’s oral history surrounding your illegitimate ancestor.  Reach out to collateral descendants, especially the older generations. The same oral history stories and information may have passed down a collateral line in your family but their version can hold different clues. 

In every case where I discovered an illegitimate ancestor’s parents, reaching out to distant cousins proved crucial.

Be sensitive in your questions when looking for information. My experience proved one aunt had no problems talking about an illegitimate ancestor, while her cousin deftly changed the topic of conversation each time the subject was broached.

antique photo of family with 4 children in searching illegitimate ancestors

Vital Records

If you are researching in fairly “modern” times when birth and death certificates were being issued, be sure to check those.  Often the father is not listed or listed as “unknown”, but you may get lucky and find the father’s name listed. Even a partial name will provide you a valuable clue.

Church Records

Evidence of a child born our of wedlock  may be found within church records. If you do not know the child’s mother, the church records may help.

A woman who had a child out of wedlock may have been censored or excommunicated from the church. Check what records are available for the location you are researching. Are there any women being disciplined by the church for having an illegitimate child around the time your ancestor was born. Or if you know the mother, do you find her being disciplined? You can pick up clues to her identity here.

Bastardy Bonds and Apprentice Bonds

Bastardy bonds and apprentice bonds  (from the colonial era up through 1913 in NC) are useful in determining one or both parents of an illegitimate child. Bastardy bonds are against the mother so you need to know the mother’s name. The father is sometimes named in these bonds if the mother was willing to name him.

Apprentice bonds are also helpful.  If your ancestor was apprenticed as a child (and this could be done at a very young age) the bond often will list the parent’s child.  For example, Dulaney Swinney was apprenticed to Atkin McLemore in Granville County, NC in 1756. Dulaney was noted to be the son of Moses Swinney.  If the child’s named parent is the mother only, then the child may have been born out or wedlock.

1750'ish apprentice bond for  Dulaney Sweeney, son of Moses Swinny

DNA Testing

The use of DNA to further genealogical research will certainly help in determining your ancestral line.  While DNA is not a paternity test and will not tell you who the father of your ancestor was, DNA can potentially provide you with a surname or line you match. DNA can  give you  new avenues of research.

Mary Eberle of DNA Hunters talks about using DNA to find unknown parents in 7 Steps for Using DNA to Find Birth Parents of Adoptees & Others with Unknown Parents  . Check out the YouTube Video, too! For an excellent DNA resource, I recommend The Family Tree Guide to DNA Testing and Genetic Genealogy by Blaine Bettinger.

Youtube Live with Mary Eberle

Consider Other Potential Clues When Researching Your Illegitimate Ancestor

Sometimes you will pick up on other clues in the records that your ancestor may have been born out of wedlock.

Consider if:

  • The mother named the child after the father giving you a clue to potential father candidate.
  • Was money involved?  If the child’s father was from a wealthy family, a woman may have sued for money to support the child.  Check the court records. [Note: Outside of bastardy bonds, I rarely find this to be the case.]
  • Illegitimate children usually took the mother’s surname. In cases where they took the father’s surname, the father generally acknowledged the child.


Researching ancestors born out of wedlock is not easy or quick. It can be a very sensitive topic within a family.  Sometimes the best we can do is build a circumstantial case with the clues we do find. Then we wait for the next bit of information…..

🤔Stuck trying to find an elusive ancestor? Ready to stop the aimless search of the genealogy databases that leaves you frustrated and still NO results?
Check out the VIP Genealogy Intensive Day where we focus on getting your genealogy research back on track with a day dedicated just to Y-O-U. 😊

Other Posts You May Enjoy

***Please note that this post contains affiliate links which means I may earn a commission if you decide to purchase a product/service. This does not cost you extra. Be assured I only recommend products/services that I use and think you would like too. Read my disclosure policy and privacy policy.


  • Janelle Holmes

    I have an illegitimate ancestor, the result of a rape of my 12 year old ancestress by her cousin. Family tradition always said Wm Johnson was her father. When I found her marriage record at the same age to another man, giving consent by her mother and father, both named, I discovered Wm. Johnson was her father. Later research proved that her rapist and father of my ancestor, was the son of her father’s full brother, who seems to have left the state shortly thereafter, married and had other children. All these children, including my ancestor are named in a lawsuit brought against his estate. This is how I discovered his father. Since his surname was the maiden name of his mother as well as his biological father, this would not have provided me with information as to the surname of his father if I hadn’t found this document. My ancestor only lived with his mother and her husband for 10 years or so and then seems to have gone to live with his grandfather. To confound matters, when he married he lied about his age, making himself closer to his much older wife in years. He was actually about 8 years younger, but the lie continued the remainder of his life.

    On researching my husband’s line I did discover a bastardy bond from the 1600s showing that a certain young woman and her sister had two children each by two neighboring brothers. You think they would have learned. Neither of these women married either of the brothers, either.

    • Sue Holmes

      I was reading Lisa’s post on how to find illegitimate ancestors and found your post. We are researching for my family as well as my husbands. We know little about both. His family is from the Indiana area and was wondering if yours is also. His father is Marion Thomas Holmes.
      Hope you can reply. Thank you
      Sue Holmes

    • Laura Noonan

      My grandfather was born in New York 1907, all documents and research shows unknown parents, can’t find any family members. Any ideas that you could point me toward to help find his parents would be greatly appreciated. All I know is his parents were from Ireland. But he himself did not know who they were.

  • Clorinda Madsen

    I have a case in my tree where son #1 was born the year dad died. Son #2 was born 4 years later but given the same surname. Many have assumed that meant dad didn’t die until after son #2 was born, but he was quite clearly dead 4 years prior in a very infamous manner. I will have to look into some of these methods to see whether we can figure things out without DNA. Since I’m not descended from that side, chances are, somebody else will have to ultimately solve/confirm things.

  • Joanne

    My grandfather was the first-born, a little more than a year after his mom arrived in NYC. Then they moved to Philly and more kids came before their dad died. His mom married two years later and her husband adopted the kids. We didn’t know about my great grandfather other than his last name was the same as my great grandmother’s, so I ordered my grandfather’s birth certificate. I was shocked when it said out of wedlock. My aunt said everyone knew they never married but they didn’t talk about it. Strangely, his name was on the other kids’ birth certificate. I’m not even sure he is my grandfather’s dad because he is the only great grandparent I can’t find a single DNA match for. It’s possible I just got the wrong names of his family members in Germany, but I don’t know if there’s any way to determine if the guy I always thought was my great grandfather really is. He also stated in his will that they were married a year after my grandfather was born, which adds more confusion.

    • LisaL

      It’s so hard to untangle family mysteries like this when the the people who knew the answers are no longer around to answer our questions.

  • Eleanor Kendall

    Eleanor April 9, 2020

    I have found out from taking the Ancestry DNA test that the man who raised me is not my real father. The test showed that my real father was Italian and lived in Toronto, Ontario, Canada. I was also born in Toronto, Ontario, Canada.

    As the mother who raised me had four other children and I was the middle child the only conclusion I can come up with is that her sister was my real mother. All the other children had white hair when born as well as the two older children had blue eyes while the younger children had white hair and light brown eyes.

    I was born with black hair dark brown eyes and very white skin. My birth certificate looks a little strange as well. The man who raised me filled it out and the Dr. who delivered me never signed the certificate, the father who raised me had filled it in.

    I was born exactly two years (or less

    I have been taken for Italian all my life. I was even in Italy about 15 years ago and I was taken for Italian by the Italians.

    I have been able to find about 15 people on my Italian side but no relatives on my English fathers side.

    I have been able to find on Ancestry family on my mothers side but none on the man who raised me side.

    The only conclusion I can come up with is that the mother who raised me was the older sister of my real mother. As I am having problems finding family on my mothers sisters side I am at a standstill.

    Would appreciate how I can continue my search.


    • Jane

      I just read your email (April 9, 2020) about finding out your father is not your real father and wondering how you can continue your search for your birth mother etc. In my (successful) search for the birth family of my son’s father, I learned that it is possible to obtain the hospital record of your birth from Ontario hospitals. This may help you identify your birth mother. If you were born in Toronto, then it is more than likely that your birth mother lived in Ontario (due to health coverage if you were born when it was in effect).
      You may also want to compare DNA with your siblings…Since we get about 50% of our DNA from each parent, if you shared a mother but not a father your DNA will be off with each of your siblings whereas their DNA will have a much higher match to each other. This will also help you isolate the father’s DNA (23andme allows you to do this). It is quite possible that although you share the same mother, your birth father is different due to other circumstances (affair, fling, rape).
      You may also want to apply for a copy of your original Ontario birth certificate to make sure the version you have is the official version that was actually registered and not a “doctored” version given to you. Yours sounds a bit fishy! Make sure you apply for the long form version.
      Good luck and let me know if you need any more help…



  • Catherine E Blount

    Great article. Thank you.

    My paternal grandfather was born in 1856 in Detroit but raised in Canada. We were raised to believe he was Irish, born to a father who divorced his Irish Catholic mother just after he was born. The story seemed suspicious to me for many reasons, but when I did DNA testing it became clear that Grandpa wasn’t who we believed him to be. He was Jewish and German and my highest DNA matches on all the major testing sites connected me to Jewish families I never heard of.

    There were no clues in census or vital records, but newspaper research pried open a door. There was a legal notice published in a Detroit paper six weeks after my grandfather was born. That article named a young man from a prominent family who was charged with “bastardy.” The name of that young man was the same as my of my DNA matches! The newspaper article named the court where the case was to be heard. Unfortunately, those court records apparently haven’t survived.

    There is still a lot of research to do. I just wanted to share how useful I’ve found newspapers in researching my ancestors. They were THE media of their day; they recorded everything. There are still many mysteries to solve in my family history, but newspaper research has proven invaluable on several occasions.

    • LisaL

      What a great story on newspaper research! I think often we overlook those legal notices, but they can hold so much information.

  • Kathryn James

    My Mother Had an Affair With a Married Man Resulting in Me. While a Few Months Pregnant She Quickly Married Another Guy and Named Him as The Father on My Birth Certificate. So Much For Birth Certificates Being a Legitimate Source Right ?

    Years Later She Took Me at Age 4 to Meet My Real Dad She Took Pictures of The 2 of Us Together.

    I Knew His Name and Many Years After I got Married I Asked My Mother What My Real Dads Name Was She Told Me and I Typed up a Affidavit of Truth, Had Her Sign It Notarized and Filed at The County Court Hose As a Legal Document.

    I Found out My Real Dad Died in 1993, So I Located a Marriage Certificate and Eventually Called His Wife. She Claimed That She Remembers The Allegations of Him Having a Daughter and at the Time Had a Good Laugh About It, Because He Had a Vasectomy Before They were Ever Married. So He Couldn’t Possibly Be My Dad. Plus He Ran Around a Lot With Many of Different Ladies and No Other Children of His Have Ever Showed Up.

    I Took a DNA test and some of the Cousins I have are related to Some of his Family. He has Step Children But I seem to be the only Legitimate Child of Him. His Wife Has Since Passed On.

  • Ruth Roberts

    My grandfather was told growing up that his mother was named Lucy Smith and died in childbirth when he was born and was buried in Texas. My mother and her siblings began researching to find her death records while he was still alive, but were unable to find a Lucy Smith in either birth or death records. After he passed away, DNA testing proved that the man who raised him wasn’t his biological father either. They were also unable to find birth records for him in any state he remembered living, Texas, Oklahoma, Kansas, and Arkansas. They tried contacting DNA relative matches, but no one had heard of him. Any advice on where or how to look next?

    • Gloria

      Have you attempted to uncover the common ancestor shared with your matches? Do your best to build a tree of one or multiple related dna matches up, and then move down until those related matches fit into the tree. You should be able to figure out where your most recent shared ancestoral couple was, then move down from there to narrow who may be parent 1 of your grandfather. Use the same technique for both sides. I’m doing the same right now, and its worked well, though has absolutely been made more difficult by his age (born 1910, deceased since 1981, had my mother as an older man, and very quiet about his past, before marriage in 1930). Best of luck!

      • Gloria

        Above comment about tips for working out grandparent’s parentage was meant in response to Ruth Roberts earlier comment.

  • Judy Purcell

    While researching my son-in-law’s family, I found a g-g-grandfather who was a county judge. I thought I had found a real nugget. Turns out he “adopted” his son. While trying to figure this out, I spoke to the eldest member of the family still alive. According to him the baby was left on the porch by gypsies and there was never a formal adoption. While I doubt the gypsy story, I suspect that the child was probably the son of the judge and another female. His wife never had a child and this “adopted” son was their only child. I can’t prove anything and there are no birth certificates before 1923. Guess we’ll never know.

  • Denise Roeller

    My grandmother had twin daughters unwed and given up for adoption ?!?! between 1908 and 1920 in West Michigan… She was married in 1922 and had 10 more children (2 sets of twins) …. My question is: How do I find my illegitimate Twin Aunts????

  • Joan McCarthy

    My mother passed away in 1974 when I was 7. I found out later that she was the result of an affair with a married man. My grandmother wrote her ex husband as the father on the birth certificate. The story I heard was the father was married and did not want to leave his many children and that he played the piano. I have done my dna and have cousins that don’t match any other family members so I assume it has to be my grandfather. Of course these cousins deny that an affair could happen. I believe their grandfather is the same as mine but it is difficult to confirm. Not sure if this helps shared dna is 410cM across 22 segments. Any tips. Joan

  • Michelle Hughes

    I am not sure if my ancestor was illegitimate or not. What I am trying to determine is his parentage, because he and his children are listed as “mulatto” on the 1910 census, and I would love to know if he is a product of a consensual relationship or the child of slave abuse. I wonder how to start looking for that. His birth records seem to not be listed with the state, so I don’t know where to go from there. He also “whitewashed” his ancestry, as by the late 1910s and 1920s, he listed himself as white. Any tips where I might start?

    • LisaL

      This is definitely a tough problem. First, go back through earlier census to see how his race was listed. See if you can find him in the home of his parents. Additionally, DNA testing can help. You might need a DNA expert to help you process the results.

  • Margeé

    My late husband was middle child of seven. No marriage lic to be found for his Mom.
    His oldest brother had a Dad, he and two older brothers had a Dad, his sister had a Dad, his Younger brother had a Dad and youngest sister had a Dad.
    What a mess!

  • marion Judy collins

    My mother was born out of wedlock. Mary Jane Lennon. Her birth certificate (not sure it is hers) states that she was born on 04/18/1923 to Morgan Johnson and Stuart Lennon. My uncle (her half brother) is convinced that it is her birth certificate. Indeed her birth date was the same, the age of the mother is correct but her mother’s given name was Helen Margret Lennon. Any clues as to how I find out about this birth?

  • Deb

    The father listed on my mother’s birth certificate is incorrect since she had an affair. The family openly acknowledges my mother is the daughter of the man she had the affair with. But they haven’t (and I doubt they would) amend or correct her birth certificate. I am interested in applying for Italian citizenship through descent since my mother was born before 1948. Would genetic testing help in this situation?

    • LisaL

      You would need to check with a specialist in Italian citizenship or an Immigration lawyer. I’m not sure if Italy will accept genetic testing.

  • Robert/Enid Herlihy

    We have been searching for Robert’s grandfather’s birthdate and birth parents of Harry McLeod.
    Supposedly born October 1886 in Moncton, NB, Canada.
    We have found nothing.
    He was brought up by his ‘uncle’ Vincent McLeod (who was from Prince Edward Island, Canada.
    We found a 1991 census from Canada that lists Harry as a ‘boarder’ (at 4 years old) with Bessie Mackenzie (another boarder) living in the household of Vincent and Louise McLeod.
    The next census is from Massachusetts in 1900 where Harry is Vincent and Louise ‘s son (but they list having no children).
    But we can’t find his biological father and mother
    Is there any help here?

  • sharryn Clark

    My Great Grandfather born 1852, was adopted papers list his Mother as Jane Jones
    Would DNA testing be of any value after such a long time?

  • Mel Davis

    My great-grandfather was born out of wedlock in 1861. By working with my 2nd cousins who were straight-line male descendants, we discovered the surname of his father. There was only one male with that name living nearby, but I think it may have been his brother. The brother was a bit older and I have found some sketchy stories about him in the newspapers. While the brother did not live nearby, I am sure he came to visit. Is there a way to prove which brother was the likely candidate?

Leave a Reply

Your email address will not be published. Required fields are marked *