Complex sentence: Hordern's contract at the Shakespeare Memorial Theatre lasted until the summer of 1952, and upon its expiration, he secured a position within Michael Benthall's theatrical company at the Old Vic in London.
Split into simpler sentences: Hordern's contract at the Shakespeare Memorial Theatre lasted until the summer of 1952. Upon its expiration he secured a position within Michael Benthall's theatrical company at the Old Vic in London.