Count Grendel of Gracht was a Knight of the nobility of the planet Tara and the Lord of Castle Gracht, his sole on-screen appearance was in the Fourth Doctor serial, The Androids of Tara, part of the Season 16 quest for the Key to Time. The character was played by Peter Jeffrey.
While searching for the fourth segment of the Key, Romana discovered that it was disguised as the head of a statue representing the family crest of Grendel’s family. After Romana transformed it into its actual crystalline form, the segment was confiscated by Grendel. Grendel did not know of the segment’s true nature; his real intent was to use Romana (who resembled the Princess Strella) in a complex plot to seize the throne of Tara from Prince Reynart.
His plans were ultimately defeated by the Doctor. Although Grendel was considered the finest swordsman on Tara, the Doctor managed to duel him to a standstill, and he made his escape by leaping into the moat of Castle Gracht and swimming away.
A cultured and charming villain, Gracht used his breeding to cover a ruthless and cunning personality. He used and discarded people as easily as he would persuade them to do his bidding, and somehow always managed to live to scheme another day. He also appeared in the spin-off short story The Trials of Tara by Paul Cornell, where another attempt to seize the throne of Tara with the help of the salvaged remains of the Kandy Man was foiled by the Seventh Doctor and Benny.