Kajkavian
The major cities in northern Croatia are located in what was historically a Kajkavian-speaking area, mainly Zagreb, Koprivnica, Krapina, Križevci, Varaždin, Čakovec. The typical archaic Kajkavian is today spoken mainly in Hrvatsko Zagorje hills and Međimurje plain, and in adjacent areas of northwestern Croatia where immigrants and the Štokavian standard had much less influence. The most peculiar Kajkavian dialect "(Baegnunski)" is spoken in Bednja in northernmost Croatia. Many of northern Croatian urban areas today are partly Štokavianized due to the influence of the standard language and immigration of Štokavian speakers.
Shtokavian
Croatian has had a long tradition of Shtokavian vernacular literacy and literature. It took almost four and half centuries for Shtokavian to prevail as the dialectal basis for the Croatian standard. In other periods, Chakavian and Kajkavian dialects, as well as hybrid Chakavian–Kajkavian–Shtokavian interdialects "contended" for the Croatian national koine – but eventually lost, mainly due to historical and political reasons. By the 1650s it was fairly obvious that Shtokavian would become the dialectal basis for the Croatian standard, but this process was finally completed in the 1850s, when Neo-Shtokavian Ijekavian, based mainly on Ragusan (Dubrovnik), Dalmatian, Bosnian, and Slavonian literary heritage became the national standard language.