In Croatia, Seiwerth families are Croats (from Djurdjevac ). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb and Djurdjevac.
Prevalence
About 10 people with faimily name Seiwerth live in Croatia today, in three households only. There were 0 of them in the middle of the past century, and their number multiplied. They are located in one Croatian city only, in Zagreb (<10).
Outside Croatia
Family name Seiwerth is present in 10 countries on three continents. The family name "Seiwerth " is used by some 300 people in Germany , small number in the United States , and small number of people in Austria.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1917 in source List of Dignitaries, Officials and Public Servants of the Kingdom of Croatia-Slavonia.