How can you expect a stable/non-corrupt to exist when your geography puts you at the mercy of powerful neighbors constantly?

Historically, they mostly ruled. Even when under the Ottomans and Austrians, Hungarians composed the landed nobility of their lands. Much of the peasantry in Hungary proper were re-Hungarianized only during the national revival. There are many books about the Hungarian language being on its deathbed in the late 18th century. In response to Latin being replaced by German in government business, they quickly got the concession to use Hungarian in education with the explicit goal of converting everyone they could into Hungarians. Within 2 more generations, they gained equal status in the empire and continued the process. (Then they lost it in 1918.)