Hungarian State Foundation Day. The date is from the canonisation of Stephen I of Hungary.
Stephen (Hungarian: István), who is remembered as the founder of the Hungarian state, was crowned as its first Christian king in 1000 AD. At Christmas, a new independent state of Hungary emerged in Europe. To commemorate him, Hungarians celebrate 20 August primarily as the day of the founding of statehood.
Stephen (c. 975–1038) became the ruler of Hungary after the death of his father, Great Prince Géza in 997. Stephen I the Holy, who sat on the throne, completed the establishment of the Hungarian kingdom.
The Kingdom of Hungary consisted of present-day Hungary, Transylvania (currently in Romania), Slovakia, Ruthenia (currently in Ukraine), Vojvodina (currently in Serbia), Burgenland (currently in Austria), Slavonia, Croatia, Dalmatia (currently in Croatia) and some other smaller territories around the modern Hungarian borders.
In 1028, Stephen I abolished the power of the tribal princes, dividing the country into comitates, or counties, headed by the king-appointed ispáns, or counts. He divided up the country’s lands among subjects and churches, thus creating a feudal system in Hungary.
As king, he also embraced Catholicism and spread it among his people. It was for this that he was declared a saint after his death.