Turkish constitutional law scholar Mumtaz Soysal, a onetime foreign minister, passed away on Monday. He was 90 years old.

Soysal had been undergoing treatment for various ailments, according to press reports.

Born in 1929, Soysal was one of the most prominent figures in Turkish constitutional law.

A graduate of the venerable Galatasaray High School in Istanbul, Soysal continued his studies of political science and the law at Ankara University in the nation’s capital.

Read more: Turkey: Scholar, ex-foreign minister Soysal passes away