Complex sentence: 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) on 23 May 1994.
Split into simpler sentences: From 1987 until 1994, he also served as the president of this Court. During his term as President of the Constitutional Court, Herzog was elected President of Germany by the Federal Assembly (Bundesversammlung) on 23 May 1994.