Complex sentence: Jan Pinborg (1937--1982) was a renowned historian of medieval linguistics and philosophy of language, and the most famous member of the Copenhagen School of Medieval Philosophy pioneered by Heinrich Roos in the 1940s.
Split into simpler sentences: Jan Pinborg (1937--82) was a renowned historian of medieval linguistics and philosophy of language. He was the most famous member of the Copenhagen School of Medieval Philosophy pioneered by Heinrich Roos in the 1940s.