alexandru, here's Pacta Conventa for you...
After king Zvonimir died, there was a civil war in Croatia, one party chose the regent Petar as king, the other the Queens' brother Koloman, king of Hungary.
In spring 1097. Koloman is petitioned by supporting nobles to invade. He defeats Petar at the battle of Gvozd. Koloman proceeded towards the coast, but had to retreat because Russians and Kumans invaded Hungary.
Croatian nobles rallied and sent an army north to Drava. Koloman was forced to negotiate, before he was coronated in Biograd na Moru, a settlement was agreed upon.
Here are the main points:
1. The King of Hungary will not unite the Kingdom of Croatia and Dalmatia with the Kingdom of Hungary, and these will remain separate independent kingdoms, each with its own crown, each with separate coronation. As proof the king new title will be:"King of Hungary, Croatia and Dalmatia"
2. The King of Hungary will rule Croatia according to the constitution in agreement with Croatian State Parliament.
3. The twelve ancient Croat tribes keep their legacy and rights and pay no taxes to the King.
4. Croat Forces, in Croatia and abroad fight only under Croatian banner and as a separate Croatian army.
5. According to the settlement, Croatian teritory is defined as all between Drava and Danube to the north and the Adriatic to the south.
The Pacta Conventa is the first personal union treaty between two independent nations: Hungary and Croatia, first represented by Koloman I and the other by the twelve Croat tribes.
This was absolute law from 1102.-1526., and the basis of everything during the Habsburg reign.