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Swedish Kin

Swedish Patronymic Names: Why Your Ancestor's Surname Changed

Swedish patronymic names changed with every generation: Anders's son Per was Per Andersson, but Per's son was Persson. This guide explains how -son and -dotter worked, when they became fixed surnames, and how to find the right person in the records.

Facts checked against sources, November 2026

Illustration of a priest baptizing a baby at a stone font in a country church, with the family around
The priest baptizes a child in a country church in the 1800s.
On this page
  1. What is a patronymic name?
  2. Why patronymic names matter when you trace your Swedish family
  3. When did -son become a surname?
  4. Timeline
  5. The same person, different names
  6. Step by step: avoid duplicates in your family tree
  7. Pitfalls
  8. Glossary
  9. Common questions

The essentials in one minute

  • In a patronymic name the child took the father's first name plus -son or -dotter: Anders's children were Per Andersson and Anna Andersdotter6.
  • Only at the end of the 1800s did names ending in -son start to be passed down as family names. Names ending in -dotter disappeared around 19004.
  • The same person can appear with different names and spellings: Hans Petersson may be the same man as Hans Pehrsson3.
  • Compare relationships, places, occupations and dates, not just the name, and you avoid duplicates3.
  • Married women did not take their husband's -son name. Look for them under their own name1.

What is a patronymic name?

A patronymic name, in Swedish patronymikon, shows who a child's father was. A son got his father's first name plus -son, and a daughter got her father's first name plus -dotter (daughter)6. If Anders had two children called Per and Anna, they were Per Andersson and Anna Andersdotter. Per's children were not called Andersson but Persson6.

So the surname changed with every generation4. That is why a father and a son in your tree can have different surnames. In the countryside, patronymic names were common until well into the 1800s5. Hans Högman writes that they were in constant use in rural Sweden, and among day laborers in the towns, until the 1860s1.

Why patronymic names matter when you trace your Swedish family

  • Your ancestor may have had more than one surname. Especially in the second half of the 1800s, a person could have different surnames during his or her life1. Craftsmen often took surnames typical of their trade1.
  • Brothers and sisters have different surnames. A brother is -son and a sister -dotter, so in the records you may believe they are not related when they are siblings3. When family names came, siblings could also take different ones1.
  • Married women kept their own name. A wife never took her husband's patronymic name1.
  • The same name can be spelled in many ways. Clerks often spelled names as they sounded. Peter could be written Petter, Peder, Petrus, Per, Pehr or Pär3.
  • The same surname does not mean family. Many people in the same area took the same surname without being related1.

When did -son become a surname?

The change came slowly. At the end of the 1800s, names ending in -son began to be passed down as family names4. Names ending in -dotter never became family names and disappeared around 19004. Since 1982 it is again possible to take a -dotter name as a surname, and since 2017 men may do so too4.

The sources disagree about 1901. The Institute for Language and Folklore (Isof) writes that the first Swedish surname ordinance of 1901 stated that everyone should have a surname4. Hans Högman writes that the 1901 ordinance did not require family names and did not ban patronymics. Only the Name Act of 1963 required everyone to use a family name1.

Illustration of a Swedish parish priest writing in a large parish book at a desk in a parish office
A parish priest writes in the parish book at the parish office in the 1930s.

Timeline

  1. 1620s

    The nobility get fixed family names. The sources give different years: the House of Nobility (Riddarhuset) was founded in 1625 according to Hans Högman1 and in 1626 according to Isof, which writes that fixed family names then began to be compulsory for the nobility4. Another Isof page mentions a rule from 16285.

  2. Late 1800s

    Names ending in -son begin to be passed down as family names4.

  3. 1901

    The first surname ordinance. Isof writes that it stated that everyone should have a surname4. Högman writes that it did not require family names and did not ban patronymics1.

  4. 1920

    Married women must carry the same surname as their husband1.

  5. 1963

    The Name Act requires everyone to use a family name1. A married woman no longer has to take her husband's surname and can keep her own2.

  6. 1982

    A new name act. Married couples can choose the man's or the woman's surname2, and a name ending in -dotter can be taken as a surname4.

  7. 2017

    The Personal Names Act. Surnames with more than 2,000 bearers become free to take, and men may take a surname ending in -dotter4.

The same person, different names

In the church records the same person can appear under different names. These are the reasons the sources give:

  • No fixed spelling. Clerks often spelled names as they sounded3.
  • Married women. A wife kept her own name. Taking the husband's surname became common only at the end of the 1800s1, and from 1920 it was required1.
  • Siblings. Siblings could take family names at different times, and it was not unusual for them to take different ones1.
  • Priests. A future priest usually had a -son name until he was ordained, and then took a clergy name, often in Latin1.
  • Craftsmen. They often took a surname typical of their trade, but only after passing the journeyman's exam (gesällprovet). Before that they had a -son name1.
Illustration of a Swedish parish priest in a black gown writing in a large church book by candlelight
A parish priest writes in the church book in the 1700s.

Step by step: avoid duplicates in your family tree

  1. Do not rely on the name alone.

    Compare several details: relationships, where the person lived, occupation, and the dates of birth, marriage and death3.

  2. Search for every spelling.

    Hans Petersson may be the same man as Hans Pehrsson3. Pehr, Pär and Per were pronounced the same and are the same name7.

  3. Choose one spelling and use it everywhere in your tree.

    A computer does not understand that Pehr and Per are the same name7.

  4. Take the name from the household examination record.

    It is the best single source for names, because people were called up there by names they knew. The birth record is the least reliable, since the priest often wrote Latin forms such as Petrus instead of Per7.

  5. Look for married women under their own name.

    Before family names came, a wife did not take her husband's name1.

Pitfalls

  • Thinking that the same surname means family.

    Many people in the same area could take the same surname without being related1.

  • Thinking that siblings must share a surname.

    A sister called Agnes Johansson and a brother called Per Andersson can be siblings3.

  • Looking for a married woman under her husband's name.

    A wife never took her husband's patronymic name1.

  • Believing that patronymics were banned in 1901.

    Högman calls this a common misconception1.

  • Writing the same name in different ways in your family tree program.

    Pehr and Per become two different names to the computer7.

Glossary

patronymikon
Patronymic name: a name made from the father's first name with -son or -dotter6.
-son
Son: Andersson is Anders's son6.
-dotter
Daughter: Andersdotter is Anders's daughter6.
släktnamn
Family name: a fixed surname that the whole family carries3 and passes down4.
namnform
Name form: another form of the same name. Kerstin is a form of Kristina, and Lasse is a pet form of Lars7.
gesällprovet
The journeyman's exam that a craftsman had to pass1.

All words in the glossary →

Common questions

What does a Swedish surname ending in -son or -dotter mean?

It shows who the father was. Anders's children were Per Andersson and Anna Andersdotter6.

Why do siblings have different surnames in the records?

Brothers got -son and sisters -dotter. When family names came, siblings could also take different surnames at different times1.

Did a married woman take her husband's name?

Not in the past. A wife never took her husband's patronymic name. Taking his surname became common only at the end of the 1800s1, and from 1920 it was required1.

Were patronymics banned in 1901?

No, according to Hans Högman, who calls it a common misconception: only the Name Act of 1963 required everyone to use a family name1. According to Isof, the 1901 ordinance stated that everyone should have a surname4.

Why is the same name spelled in different ways?

Clerks often spelled names as they sounded. Pehr, Pär and Per are the same name3,7.

Are we related if we have the same surname?

Not necessarily. Many people in the same area took the same surname without being related1.

Where do I find the name my ancestor actually used?

In the household examination record, where people were called up by names they knew. The birth record is the least reliable, because the priest often wrote Latin forms7.

Sources

Sources in English

  1. Hans Högman: Naming practice in Sweden – hhogman.se
  2. Hans Högman: Name laws in Sweden – hhogman.se
  3. FamilySearch: Swedish Last Names – familysearch.org

Sources in Swedish

These pages are in Swedish.

  1. Isof (Institute for Language and Folklore): Efternamn (in Swedish) – isof.se
  2. Isof: Historik om personnamn i Sverige (in Swedish) – isof.se
  3. Isof, Namnbloggen: Andersson – Sveriges toppnamn, 1 December 2021 (in Swedish) – isof.se
  4. Sveriges släktforskarförbund (the Federation of Swedish Genealogical Societies): Bakgrund till namnlistan (in Swedish) – rotter.se