The Beatles biopic is officially happening, which means it's time to brush up on all there is to know about the Fab Four.

To the disappointment of many, McCartney was engaged to actress Jane Asher at the height ... artist when she met Paul, and after the Beatles broke up in 1970, the couple became musical ...

He had written 'A World Without Love' when he was 16 and when Paul moved in with then-girlfriend Jane Asher ... follow up to their number one, before the pair recorded another Lennon-McCartney ...