In Croatia, Sen families are predominantly Croats (from Karlovac ), rarely Hungarians (from Beli Manastir area ), and . In the past century, relatively most of Croatian residents bearing this family name were born in Karlovac and in Beli Manastir area.
Prevalence
About 20 people with faimily name Sen live in Croatia today, in five households only. There were 30 of them in the middle of the past century, and their number decreased by 50 percent. They are located in only five naselja i to in Rijeka (<5), Karlovac (<5), Mahicno (<5), Vuksic (<5), and in Bilje in Osijek area (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1917 in source List of Dignitaries, Officials and Public Servants of the Kingdom of Croatia-Slavonia.