Complex sentence: He had a girlfriend, but was taken away from him when the owners of them had divorced and the girl owner moved away and took his girlfriend with her and has been locked up in a shed for many years until Gnomeo and Juliet released him.
Split into simpler sentences: He had a girlfriend, but was taken away from her when their owners divorced (and the ex-wife subsequently moved, taking Featherstone's girlfriend with her). He was then locked up in a shed for many years until Gnomeo and Juliet released him.