Whether a "Burgmann" was a free knight, "dienstmann" or ministerialis, he was a member of the aristocracy who was charged by the Burgrave or lord of the castle (the "Burgherr") with the so-called "Burghut" or castle-guard. In other words, his job was to guard the castle and defend it in case of attack. A fief had to be defended from incursion and the supporting farmland had to be run correctly, proper repairs and improvements had to be made, possibly fortifying key points and collecting taxes. Ministeriales replaced free nobles as castellans under Conrad I of Abensberg's tenure as Archbishop of Salzburg from 1106 to 1147. In 1131, Hohensalzburg saw its first ministerialis, Henry of Seekirchen, sit as both burgmann and burgrave, overseeing a permanent garrison of subordinate (free) knights.