Prince Karel Schwarzenberg, who has died aged 85, was the head of one of Europe’s oldest aristocratic dynasties, and eyewitness to the turmoil visited on central Europe in the 20th century; exiled from his family lands in Czechoslovakia in 1948, he was an active participant in the movement which ousted the communist regime of Miloš Jakeš, and returned to Prague in 1989 after the Velvet Revolution led by Václav Havel.