Two events marked Hans Adam's assumption of the formal rights and duties of a sovereign prince of Liechtenstein. On 4 July 1983, Prince Franz Josef II announced his intention of turning executive power over to his son. This was accomplished in a formal ceremony on 26 August 1984.
At the death of his father on 13 November 1989, Hans Adam became the thirteenth ruling prince of Liechtenstein, as Prince Hans Adam II. His mother had died only a month previously. The prince's official title is His Serene Highness Prince Hans Adam Pius von und zu Liechtenstein, Duke of Troppau and of Jagerndorf, Court of Reitburg.