Walther_von_Dyck--Christian_Felix_Klein

Walther Franz Anton von Dyck (6 December 1856 – 5 November 1934), born Dyck (German pronunciation: [diːk]) and later ennobled, was a German mathematician. He is credited with being the first to define a mathematical group, in the modern sense in (Dyck 1882). He laid the foundations of combinatorial group theory, being the first to systematically study a group by generators and relations.