Rožmberk Castle was probably founded by Vok the Ist of Rosenberg around the middle of the 13th century. Later, repeated extensions to the castle were made, the watchtower and defensive tower later known as Jakobínka, an essential part of the complex, and a landmark visible from afar, being one of them.
In 1412, it was first mentioned in written sources that the castle complex consisted of two parts - the so-called Upper and Lower Castles - with their own administrators (burgraves), and at the beginning of the 16th century it was reported that the Upper Castle garrison included two armed guards on “the tower”, probably a reference to Jakobínka.
On 9th April 1522, a large fire broke out at Rožmberk, during which, according to the Rožmberk chronicle, “the upper castle with its round tower also burned down…”. The stone masonry of the tower certainly resisted the fire and only its wooden floors, stairs, roof, and gallery could have burnt. Repairs probably followed very quickly, as the wooden structure supporting the newly built brick vault and the supporting beams between the individual floors of the tower came, according to dendrochronological dating, from trees felled in 1523.
In the following centuries, only minor repairs to Jakobínka took place, for example, its shingled roofing, painted red, was repeatedly renewed. When the then owners, the Buquoy family, rebuilt the castle in the Romantic Neogothic style in the middle of the 19th century, they perceived Jakobínka as a symbol of its antiquity. The castle inventory states that “… the so-called tower of Jakobínka, built of stone and lime mortar, stands as an ancient ornament of both Rožmberk castles in the new castle park”. The Buquoys were also interested in making the tower more accessible, so, in 1858, they built a new entrance on its ground floor and a spiral staircase inside allowing access to the upper floors. Originally, the tower was entered via an external wooden staircase to the portal at its middle.