Complex sentence: He learned his craft in the 1920s with a touring company and later the Birmingham Repertory Theatre, before joining the Old Vic where he led the company in 1931, succeeding John Gielgud, from whom he had learned much about stagecraft.
Split into simpler sentences: He learned his craft in the 1920s with a touring company and later the Birmingham Repertory Theatre. He later joined the Old Vic where he led the company in 1931, succeeding John Gielgud, from whom he learned much about stagecraft.