The Rosenberg family (Rožmberkové in Czech, sg. z Rožmberka) was a significant and influential Bohemian noble family, playing an important role in Czech medieval history from the 13th century until 1611. Members of this family held posts at the Prague royal (and later imperial) court and were viewed as very powerful lords of the Kingdom of Bohemia. This branch of the Vítkovci clan was initially founded by Vítek III, the son of Vítek (German "Witiko") of Prčice.
Around 1250, the Vítkovci clan settled at the Rožmberk Castle in the region of Český Krumlov, then about 1253 erected the Český Krumlov castle. The Krumlov castle thus became the residence of the Lords of Rožmberk for the next three hundred years. It was the Rožmberks who influenced the appearance of southern Bohemia to a great extent.
The coat of arms and emblem of this family was represented by a red five-petalled rose in a silver field, which is still often seen in a considerable part of southern Bohemia.
Peter I of Rožmberk held the post of the superior chamberlain at the court of John of Bohemia. His wife was a widow of the Bohemian king Wenceslaus III.
Another significant personage of the family was Jindřich III of Rožmberk, a son of Oldřich I, who led the Union of Nobility, being displeased during the reign of King Wenceslaus IV.
Jindřich's son, Oldřich II of Rožmberk, was a member of the Bohemian nobility who defended the interests of Bohemian catholic nobility and of Sigismund, Holy Roman Emperor, during the times of the Hussite wars.