• Stefan Israel

Understanding -Sen and -Son in a Name: Johnson, Janson and Jansen

Why do some family names end in -son, and some in -sen?


the short answer

-sen is typically a Danish or Dano-Norwegian ending, meaning ‘son of’

Jensen, Hansen, Pedersen (son of Jens/John, of Hans, of Peter)


while Swedes, and Icelanders, use -son or -sson,

Andersson, Johansson, Karlsson, Jakobsson


but so did the English,

John's son > Johnson

William’s son > Williamson or Wilson

Nicholas’ son > Nixon

Richard’s son > Richardson or Dick’s son > Dixon


and occasionally you get an anglicized German or Dutch name

Willemssohn > Williamson

Hendrik Albertszen > Henry Albertson


Earlier on, since -son literally meant ‘son of’, daughters had of course to be called ‘daughter of’, read on for that and more.


the long answer

The first thing to know is that they are all, originally, patronymics, which is a fancy word for ‘name of your father’. In lots of cultures, you’re identified by who your father was- David’s son was Davidson, the Bible’s son of Jonah was called Bar-Jonah, ‘Jonah’s-son’ (today many are more familiar with his name Peter), Jack’s son became Jackson etc. Lots of languages do that.


In Germanic languages, the old tradition was, you had one name, and then you stated your father’s name: Erik Waltersson was Erik, Walter’s son. Erik’s son Harold would be Harold Eriksson, while Erik’s daughter Hilda would be Hilda Eriksdohter.


The insistence on unchanging family names tended to come from the rulers, who wanted to keep track of who inherited what, and who to tax on what.


The further north you got, away from the more urbanized Mediterranean, the longer this older naming convention lasted.

Southern Germany and England adopted fixed family names in the Middle Ages.

Northern Germany was switching in the 1800’s.

Napoleon enforced family names on the Dutch by fiat starting 1811.

Denmark decreed family names by law in 1856, Sweden banned the practice in 1901 (the trend was already underway since the 1700’s).

Rural Norway finally adopted unchanging family names by 1900, and codified by law in 1923.

The three big Scandinavian countries have since eased up and allowed you to use patronymics/matronymics if you really want to; Iceland generally bans family names.

In Iceland, that is still the law: one given name, plus dad’s name. In small villages, that’s all you needed. Now that Reykjavik is over a hundred thousand people, the phone books have to list your name, your patronymic, your address and your profession, so people know which of scores of Jon Jonsson you are.


All right, but still, why -son, why -sen?

The answer is: Swedish still spells and pronounces it with an -o-, and still spells it -son. The Danes reduced the -o- to an uh sound, and so they spell it -sen; the Norwegians tend to follow Danish spelling, since they’d been part of the Danish realm for centuries.


All those first-name-plus-sen names are Danish or Norwegian; most of the -son names are Swedish.






John Hanson was the 'first president of the United States' - that is, he was the first president during the Articles of Confederation, 1781, before the Constitution and President Washington in 1788.


Not every -son is Scandinavian. A few are Anglicized German -sohn or Dutch -zoon (both rhyme with ‘own’),

Northern Germany: Wilhelmssohn, Felix Mendelssohn of Hamburg, Jakobsohn, Robertsohn, Petersohn

Dutch: Albertszoon, Corneliusz (short for Corneliuszoon), Hendrix (Hendrik's, that is, Harrison/Henry's son)


Dutch was particularly variable: they may have the -datter/dotter or -son or turn it into -sen, -son, -soen, -zoen, -soon, -zoon etc.

A -tse indicated a daughter: Everts (Evert’s son) or Evertse (Evert’s daughter)


and some are English:

Wilson = Will’s son

Dixon = Dick’s/Richard’s son (or Richardson)

Nixon = Nicholas’ son

Nelson = Niel’s son (and occasionally Eleanor’s son)

likewise Jackson, Dobson, Benson, Tomson, Harrison, Robinson etc.


or with an endearing diminutive -kins-

Jenkins from ‘Johnniekins’

Wilkinson from Williamkins/Willikins etc

Simpkinson from Simonkins

Atkinson from Arthurkins

Watkinson from Walterkins

Tomkinson from Tommiekins

Dickinson from Richard + kins


The names aren't always obvious: Saunderson from Sandy, that is, from Alexander, or Perkins from Peterkins. Dobson is really non-obvious- it's from Robert. Robert was, over a thousand years ago, originally Hrodaberht, yielding the nickname Dobbe anciently, and from there Dob's son, while Hrodebert itself turned into Robert (and Robin and Bob etc.).


Always keep an eye peeled for variants: 'William’s son' can turn up as Williams, Williamson, Willis, Wilson, Wilks, Wilkins, Wilkinson, Wills, Willison, Bill, Bilson, Willet, Willemot, Wilmot, Till, Tilly, Tillot, Tilson, Tillotson, Willy etc.


That possessive -s was sometimes Latinized into -i, to show off the person’s learnedness, so Jakobssohn becomes Jacobi. People with learning liked to show it off.


I'd like to end with my favorite Hans' son,



Jim Henson.


Read about the feminine endings on many names and words in this previous post.

Do you have any German, Danish, Dutch, Swedish or Norwegian documents you can't read? We can help. Find out more here.

All images in this posting are licensed through Wikicommons, except for the Jim Henson, licensed through Creative Commons.

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