Genealogy 101: Understanding Family Tree Relationships

A family tree is an excellent visual tool for exploring your family genealogy. Whether you are retracing your heritage for a school project or wanting to learn more about your family, researching your family tree history can help you uncover a deeper understanding of who you are and where you came from.

Illustration: the family tree of Sigmund Christoph von Waldburg-Zeil-Trauchburg, late 18th century
Illustration: the family tree of Sigmund Christoph von Waldburg-Zeil-Trauchburg, late 18th century. Credit: Wikimedia Commons.

Despite the seemingly simple concept of the family tree, there are specific genealogy and kinship terms that can be confusing to understand when starting your family tree research. With that in mind, we’re sharing this guide to explain the different family tree relationships.

Affinal v. Consanguine

When attempting to build anything other than your immediate family tree, you will inevitably run into some new terminology. “Affinal” and “consanguinity” are the two most important of these often-unfamiliar genealogy terms. Understanding their definitions is critical, as they will take you down two very different paths.

  • An affinal relationship is a kinship term meaning “by marriage.” On any family tree, an affinal relationship is signified by the term “in law.”
  • Consanguinity is translated directly as “of the same blood,” or in other words, a blood relation. Your parents, (great) grandparents, uncles, aunts, brothers, sisters, and cousins of various degrees are all a part of your consanguine family tree.

When exploring your family tree history, it is important to make the distinction between those to whom you are bound by marriage and those to whom you are bound by blood. The rest of this guide will exclusively explore the blood relationships. However, you can just as easily apply many of the kinship terms used for blood relations to your spouse or partner by adding “in law” as a suffix to their title.

Genealogy Terms: The Great, Grand, and the Great-Great Grand

When constructing your family tree, it is essential that you consider the irreplaceable roots without which you would not exist: your parents, their parents, and their parents’ parents. Your grandparents can be the key to correctly placing your uncles, aunts and their children (your first cousins) into your family tree.

Great-grandparents and great-great-grandparents are often harder to trace, connect, and find a record of, as there are many branches of cousins that emanate from them. A great-grandparent is the parent of your grandparent and a great-great-grandparent is the parent of your great-grandparent.

Generations before great-great usually go by numerical terminology. For example: third great-grandparent, fourth great-grandparent, and so on. Using this terminology avoids an extended repetition of “great-great-great-.”

The generation gaps that exist between great-grandparents (and beyond) and ourselves can often lead to a loss of information and family records. As such, tracing these relatives can help you find other ancestors and expand the branches of your family tree.

Cousin Kinship Terms: Degrees and Removed

During family gatherings and your research, you may have heard the phrase “third cousin twice removed” and marveled that anyone could possess such a relation. It’s quite common to have third cousins twice removed, not to mention a whole slurry of other seemingly impossible family tree relationships.

Illustration: a chart illustrating the different types of cousins, including genetic kinship marked within boxes in red which shows the actual genetic degree of relationship (gene share) with “self” in percentage (%)
Illustration: a chart illustrating the different types of cousins, including genetic kinship marked within boxes in red which shows the actual genetic degree of relationship (gene share) with “self” in percentage (%). Credit: Gringer; Wikimedia Commons.

Degrees of Cousins

There are a few degrees of relationships with your various cousins to know when it comes to your family tree:

  • First cousins: those who have the same grandparents as you but are not your siblings.
  • Second cousins: those who only have the same great-grandparents as you.
  • Third cousins: those who only have the same great-great-grandparents as you.

The term “removed” is a signifier of how many generations apart you are from that specific cousin. For example, your second cousin twice removed is the grandchild of your second cousin, as they are removed from you by two generations.

Table of Consanguinity

While understanding and tracing all these relationships can be confusing, a table of consanguinity exists to save us all from the headache of counting our family tree relationships out. The table helps to take you step-by-step through your relatives, from your great-grandparents to your great-grandchildren and everyone in between. Establishing how everyone is connected can help you learn more about your ancestors and trace the different families in your family tree.

What’s Next? Build Your Family Tree!

A family tree can go back many generations and expand across many related families. However, tracing every relative and their records to help fill in all the details can be difficult. Memories fade, family records are lost, and stories are forgotten. After collecting as much information from your relatives as you can, use online genealogical resources to help you learn more.

Local newspapers published countless stories about the people in their communities. Many newspaper articles are the only remaining record of an ancestor. Use GenealogyBank’s Historical Newspaper Archives to research and get to know the people behind the names on your family tree.

25 thoughts on “Genealogy 101: Understanding Family Tree Relationships

    1. Sorry I’m late to the party. That said, I devised a generational numbering system for identifying my ancestors, as well as other relatives and inlaws. I’ll be happy to explain if you are still interested.

  1. This is helpful info, but still does not address what I think is a more important issue for many of us: what term can be used to describe a half-sibling raised by a different family than the birth family? For instance, my half-brother was adopted and raised by a wonderful family. I value his relationship to my mother and my immediate family, and I value my (more tenuous) relationship to his family of nurture. Likewise, my mother’s mother was adopted. While I am researching what I can, I may never know her birth parents -– only her adoptive parents, and records indicating THEIR parents. What term should I use to describe that relationship?

    I can tell you that I value the loves, positive values and cultural contributions those non-birth parents have introduced to my family line. To varying degrees, they HAVE shaped my current family. I’m interested in their family lines and history as much as that of my blood relatives. Surely genealogists have developed some terminology to use for these relationships.

  2. What if a child is adopted and not blood, but you want them a part of your family tree and they are not an in-law? Thanks.

    1. That’s a great question, Beverly! “In the case of adoption, the ties of love are generally stronger than ties of blood…” (Quote taken from (Site visited Nov. 13, 2018.)

      I would recommend reading through that entire article. It will give you insights on different options for creating family trees involving adoptions.

      If you have an account at, they’ve got a step-by-step guide on how you can list adoptive parents or adopted children in your tree on their site. (See

  3. Excellent point, KWight! As someone who gained two older siblings by adoption, I can appreciate your comments. These relationships are priceless, and language should find a way to address this situation in a respectful manner.

    The following is an excerpt taken from FindMyPast ( Nov. 13,2018):
    “Your language requires a thoughtful approach. Certain words and phrases feel tainted with judgment to some people involved in the adoption process. Adoption professionals and social workers avoid potentially hurtful phrases by using Respectful Adoption Language. Especially if you are talking to adoption professionals during a search, it helps to speak their language.

    “It is more accepted to say a person ‘was’ adopted, not ‘is’ adopted. The process of legally joining a family took place in a courtroom long ago. Adoption is a legal process, not a condition.
    “‘Birth mother’ and ‘birth father’ replace ‘natural mother’ and ‘natural father’ to avoid implying an unnatural relationship between a child and adoptive parents.
    “Birth families ‘make an adoption’ plan rather than ‘give up’ a child. Consider how different those phrases sound, and how each might feel to sensitive ears.
    “‘Adoption triad members’ are anyone whose name might appear on a birth certificate: a child, birth parents, and adoptive parents.”

    We might recommend that you further familiarize yourself with adoption-related terms by reading the Wiki on “The Language of Adoption” (See

    For legal adoption terms, check out

    Another good site (showing both positive and/or potentially outdated terms) is done by Friends in Adoption. (See

    As far as genealogists’ terminologies are concerned, it’s up to the individual genealogist which style of terms they ultimately opt to use. That said, we trust that you will be able to find and utilize the best terminology (in the aforementioned links) for yourself to better convey the spirit of those unique and wonderful relationships.

  4. This is a helpful article, but I notice that my specific question is not addressed, and the provided graphic left me still wondering: My “grand”mother’s sibling is my “great” uncle or aunt, but my sibling’s “grand”child is my “grand” niece or nephew.
    This strikes me as inconsistent, and I’m confused. If my grandmother’s sibling is my great, shouldn’t my sibling’s grandchild be my great also? Or vice-versa?
    I hope you have a consistent answer for me!

    1. Louise,

      Consistency is key for you to maintain your sanity as a genealogist, so brava for your aspirations for this quality of work!

      To answer your question, “great” and “grand” are oft interchangeable. Oxford Dictionary Online has the following entry for grand-aunt (See (

      “Definition of grand-aunt in English:
      another term for great-aunt”

      This interchangeability often causes some confusion on the part of people as to what to call people–be it “great” or “grand”.

      That said, the Legal Genealogist says that the answer to your questions may be one and the same: Yes. (See

      You may read a whimsical answer here:

      Ultimately, you’re right–consistency is key. If you opt to call someone “great” or “grand”, just make sure you define your terms beforehand. That way your consistency will help others’ heads stop spinning around the conundrum that is better known as the English language.

  5. My half-brother was legally adopted by my Mother’s sister. My Mother is his biological Mother. I’m not sure how I should connect him in my Tree. Any suggestions would be appreciated.

    1. Cheri,

      Most family tree (sites & software) nowadays have the option for you to be flexible (which is needed) when dealing with situations like this. You may label your half-sibling as having been legally adopted by your maternal aunt. She would then be listed as his adoptive mother while he’d show her as having adopted him. At the same time, your and his mother would still feature in his line as his birth mother.

      Another suggestion might be for you to look at blended family trees. Those usually show step-mothers/fathers, but the point is to get an idea of how trees might look when step-siblings are involved. You can always adjust templates to meet your family’s unique dynamics.

  6. In the modern age, I have found DNA cousins whom I happen to know exist because of a family member having participated in fertility clinics, etc. They probably will never know their true biological parent, as no adoption ever took place. Is there a way to handle this in a Family Tree?

  7. Al,

    That is a great question!

    I wish that I had a profound answer for how best to approach this, genealogically-speaking. I’m going to steer you to a site called Their primary purpose is to assist in creating support, validation, and connection with anyone involved in the donor process. They have a wealth of resources ( that might be of assistance to you.

    I hope that this helps!

  8. I am creating different tree names relating to me. Do I use my name as myself for every tree I have? Another question I have. Do I use the name as far back as I can go on a different tree name? Instead of creating different tree names do I just add on my main tree line as me and add to it?

    1. Debbie,

      You’ve asked some really good questions there. To start from first to last, it depends upon the type(s) of tree(s) you are trying to create. (

      I’d highly recommend that you read this article–“How to Properly Record Names in Genealogy” ( It would also help for you to keep in mind one of my favorite rules for creating any sort of genealogical trees/charts/etc.: Consistency is key.

      Yes, you will take names as far back as they can go. As anyone can tell you, though, names can and do change for many reasons. For your “main” tree, I’d recommend that you do what you stated–start with yourself and branch out as far back as you can go.

      That’s half the fun of genealogy work–see that family tree of yours getting more and more names of people who helped make you who you are! I wish you the best in your efforts!

  9. Hi, my question is this: My great grandfather married his first wife, who died a year later. They had no children. Should I be in her family tree?

  10. Jeri,

    I’m glad that you brought this up!

    Your great grandfather’s first wife would not have you in her family tree, but she should absolutely be in yours! Since she bore no progeny, her tree would exclude you. However, since she ties in to your line–via marriage to your great grandfather–I would absolutely include her in your tree! Though the marriage may have only lasted a year before she passed away, her connection to your great grandfather has her as an important part of your family’s story.

    “We all matter in this rich tapestry of the human family.” –Steve Rockwood, FamilySearch CEO.

  11. What do you suggest I use for an unnamed ancestor in my tree? I heard “Unknown” is not a good choice. Thank you.

    1. Dear Debbie,

      You have hit on an interesting topic with varying opinions on how to handle such situations in genealogical research.

      Tamura Jones feels very strongly about this topic (she gets more into what “fantasy names” are at the URL below):
      “Do not make up names. Never make up names. If there is no name, just accept that there is no name.
      Do not enter some fantasy name you like to think of as a place holder.
      The name fields are for actual names, not your fantasy. When you do not know a particular name part, simply leave the field blank. Do not enter a fantasy name.” –Tamura Jones, “Genealogy Name Basics” in her webpage at (accessed 7 May 2019).

      ThoughtCo elaborates on this idea with their “8 Rules to Properly Cite Names in Genealogy.” Rule #3 states:
      “Enter women with their maiden name (surname at birth) rather than their husband’s surname. When you do not know a female’s maiden name, insert only her first (given) name on the chart followed by empty parentheses (). Some genealogists also record the husband’s surname. Both ways are correct as long as you are consistent and follow all naming rules. In this example, your ancestor Mary Elizabeth’s maiden name is unknown and she is married to John DEMPSEY. Example: Mary Elizabeth () or Mary Elizabeth () DEMPSEY.” — ThoughtCo, “8 Rules to Properly Record Names in Genealogy,” at (accessed 7 May 2019).

      I tend to agree with what you and these sources say on the matter. If unknown, leave the name blank (parentheses are a good option). Now that you have these unknown names on your tree, let that be your next project: discover those names! Happy hunting!

  12. Live-in partners are becoming commonplace. I understand that after 7 years in some states, that constitutes “common law” marriage. But it seems to me a young couple avoiding the expense and hassle of a wedding but intending a lifetime relationship need a place on the tree. Can you give us some guidance on this?

    On the other hand, when a marriage is quickly discovered to be a mistake and annulled or divorced within a few months with no progeny, is it still needed to be listed in the tree?

  13. Kirke- You are correct it is more common to have a live in partner at this time. As information regarding “Common Law” marriages try this link for a more detail explanation of “Common Law marriages”.
    I found some information in an message board article in about putting information in a family tree for “Couples never married”.
    As for putting information about annulled marriages without children involved and divorce,
    it could be a matter of personal preference, but I think it should be noted with a source for the couple, because at some time this will show in a record and cause confusion if not explained. Best to be upfront, it will probably come out sooner or later.

  14. Hi there GenealogyBank! I have a question about the “number of degree” in the family.
    I have an auntie who financed my college studies way back in the year 2006. She is the first cousin of my father.
    Now my question is: I and my auntie were related to what extent of degree? First Degree Aunt? Second Degree Aunt? Third Degree Aunt?
    Please let me know. Thank you in advance for your response.

    1. Thanks for your question.

      According to Wikipedia, “Commonly, ‘cousin’ refers to a ‘first cousin,’ people whose most recent common ancestor is a grandparent.[1] A first cousin is a third-degree relative and used to be known as a cousin-german, though this term is rarely used today.”
      –“Cousin-german definition and meaning | Collins English Dictionary.” Retrieved 2018-02-26.

      So we believe that would make your aunt a third degree aunt.

    1. Dear Rich,

      Good question. You would call the spouse of a niece a niece-in-law and the spouse of a nephew a nephew-in-law.

Leave a Reply

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

This site uses Akismet to reduce spam. Learn how your comment data is processed.