Archaeologic sources show that the first Slavs came to the region of Český Krumlov in the 6th century AD. Similar to Prehistorical times not many people lived here. There would be no significant population growth until the 13th century. The Slavs, like their ancestors (e.g. the Celts), built hillforts and cairns. The oldest known Medieval residence in South Bohemia was found in the area of Český Krumlov, at a place where the castle is currently situated.
Even though early-Medieval findings were not much different from Prehistoric ones, a gradual progress in building can be seen. Masonry constructions based on stones held together by grout are considered as the main defining difference between the two eras. Such a unique monument is preserved in the South Bohemian hamlet of Boletice (this location is considered the oldest early Medieval centre of the region), with its original Romanesque church of St. Nicholas.
Another important cultural expression of the transition from Prehistory to the Middle-Ages was the introduction of writing.
Whereas to some civilizations writing had been well-known for several centuries BC, the first written records in Český Krumlov's region are documented from the end of the 12th century AD. Later, in 1253, a first written note about a place called „Chrumbenowe“ appeared („Crumlovia“ in Latin lists). This name was taken over by the German language as „Krumme Aue“ (which probably refers to the curving meanders of the Vltava river) which finally gave the town its name.
A few centuries had passed between the entry of the Slavs and the first written record of Krumlov. Therefore we will now shortly focus on the main influences of power in this area.
Around the 9th century the dynasty of Slavníkovci and a tribe of Doudlebové started to assert themselves. By 995 AD the Slavník dynasty had completely been murdered out by the Přemyslid dynasty, who probably were their relatives. Due to this act the Přemyslids acquired the whole property of the Slavníkovci, so they could use it to their own liking. Thus, in the second half of the 12th century all estates in South Bohemia came in the hands of Vítek of Prčice. Why exactly him? He used to help the Czech Přemyslid prince, so in return he gained this property and the privilege for his descendants to inherit it. Vítek of Prčice divided his estates among his four sons (not five, as legend tells), one of which, Vítek II Senior, was a predecessor of the Lords of Krumlov. This important historical incident, known as „Division of the Roses“, can be seen on a picture, which is part of the castle guided tour I. It is also reminded every year at The Five-Petalled Rose Celebrations.
The dynasty of Vítkovci had climbed up to become the most powerful ducal family in the country, and King Přemysl Otakar II himself was the only one who tried to stop their increasing influence. It was the King who gave instruction to build a monastery in Zlatá Koruna – as a counterpart to the one in Vyšší Brod, which belonged to the Rosenbergs (one of branches of the Vítkovci). In the beginning of the 14th century the Krumlov branch of Vítkovci died out. After complicated negotiations between Jindřich of Rožmberk and King Václav II all their surviving estates fell to the Rosenbergs. Precisely because their government lasted for over 300 years, they gave the final shape to Český Krumlov as we know it now. Already at the very beginning of their reign they made Český Krumlov the capital family residence, so the town enjoyed an unprecedented boom. First, it naturally expanded nearby the castle (the place is now known as Latrán street), in the next phase building continued even across the river. It was especially the trade, the handicraft and new Burgher houses that prospered most. By the end of the 14th century, about 100 new houses had already been built, including the square.
Peter I of Rosenberg, an important personality of this period, built both of Český Krumlov's churches – the one of St. Vitus, the of St. Jodocus and also the chapel of St. George (nowadays it is to be seen in the castle guided tour I). He invited the representative of religious order of the Poor Clares and the Franciscans. With a king's permission, he also invited the Jews to the town, to manage the Rosenberg finances. His great-grandson Oldřich II of Rosenberg influenced the town's fade during the Hussite wars. At first, he supported the Hussites, so he expanded his property at the expens mainly of the Zlatá Koruna monastery. Thereafter he converted back and on his court he provided a refuge to significant Catholic and artistic personalities expelled from Prague. Hereby he personally helped to disseminate the ideas of Renaissance and Humanism in Czech area.