In Croatia, Hadler families are Croats (from Osijek ). In the past century, relatively most of Croatian residents bearing this family name were born in Osijek and in Banat, Vojvodina.
Prevalence
Only a few people with faimily name Hadler 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 Osijek (<5) and Djakovo (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over twenty times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.