Short answers, pulled from the story.
The Beatles formed in Liverpool, England during the late 1950s with John Lennon starting a skiffle group called The Quarrymen in 1956. Paul McCartney joined that band after meeting him at a church fete in July of 1957 and George Harrison became a member shortly thereafter when he was only fifteen years old.
Ringo Starr replaced Pete Best on drums in August of 1962. Stuart Sutcliffe played bass for them until he left to study art in Hamburg before this change occurred.
Sgt Pepper Lonely Hearts Club Band arrived in May of 1967 with complex orchestral arrangements. George Martin produced many tracks using tape loops and backward recording techniques.
Paul announced his departure from the group in April of 1970. The remaining three continued working together until the official dissolution later that year.
Peter Jackson directed a documentary film titled Get Back released in November of 2021. The band's estate has licensed songs for video games and commercials since the 1980s.