In Croatia, Gleich families are Croats (from Zagreb ). In the past century, relatively most of Croatian residents bearing this family name were born in Zagreb.
Prevalence
Only a few people with faimily name Gleich 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 one Croatian city only, in Zagreb (<5).
Outside Croatia
Family name Gleich is present in 27 countries worldwide. The family name "Gleich " is used by some 3000 people in Germany , about 1000 in the United States , and some 400 people in Madagascar.
In the sources analysed in the project Acta Croatica so far, the name is mentioned few times, the first time 1902 in source Hartmann's General List of Apartments in Zagreb.