In Croatia, Sir families are Croats (from Virovitica ). In the past century, relatively most of Croatian residents bearing this family name were born in Virovitica.
Prevalence
Only a few people with faimily name Sir live in Croatia today, in two households only. There were 0 of them in the middle of the past century, and their number remains constant. They are located in two Croatian cities only, in Cakovec (<5) and Virovitica (<5).
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.