 Blatná is also the seat of the Municipality with Extended Competence and Municipality with Commissioned Local Authority within the same borders.Although the area has been inhabited since the 6th century, the first written record of Blatná dates back to 1235, when probably just a wooden fortress built on a rocky piece of land in the middle of a marshland ("blata" in old Czech, hence the name Blatná - A Marshy Place) existed.Not much is known about the castle until the second half of the 13th century, when it becomes the property of the house of Bavorové of Strakonice.