Answer
The two presidents who served two complete five-year terms were Theodor Heuss and Richard von Weizsäcker. Heuss was president from 1949 to 1959, and Weizsäcker was president from 1984 to 1994. Heuss was a member of the Christian Democratic Union, and Weizsäcker was a member of the Social Democratic Party. Heuss was a professor of political science, and Weizsäcker was a diplomat.