Relković families are Croats and they are mostly from Nova Gradiska area. In the past century, relatively most of Croatian residents bearing this family name were born in Nova Gradiska area and in Nova Gradiska. In Davor in Nova Gradiska area every fourtieth inhabitant had the family name Relković.
Prevalence
About 100 people with faimily name Relković live in Croatia today, in 40 households. There were 50 of them in the middle of the past century, and their number doubled. They are located in 7 Croatian counties, in 10 cities and 8 other places, mostly in Davor in Nova Gradiska area (35), Zagreb (30), Zapolje in Nova Gradiska area (15), Sisak (<10), and in Gvozd in Glina area (<5).
In the sources analysed in the project Acta Croatica so far, the name is mentioned over five times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.