Original: From 1987 until 1994, he also served as the president of this Court, until he was elected President of Germany by the Federal Assembly (Bundesversammlung) in 1994.
Simplified: In 1983 he became vice president of the Federal Constitutional Court of Germany in Karlsruhe, and president over from 1987 to 1994, when he was elected President of Germany by the Bundesversammlung (Federal Convention).