Defending Wimbledon singles champions entered only the final until 1922.
Before 1922, Wimbledon used a format known as the Challenge Round. The previous year’s champion received an automatic place in the final, while the other entrants competed in an “All Comers’” tournament to determine the challenger. The defending champion then played just one match to retain the title.
The arrangement applied to the singles events and helped explain why champions could dominate several consecutive years without playing every round. It was a major structural difference from the modern knockout draw, in which every defending champion must progress through the tournament from the opening round.
The 1922 Championships ended the practice. All defending champions were required to enter the main draw and play through the rounds like everyone else. That edition was also the first Wimbledon held at the present Church Road site. The change is sometimes confused with the 1968 start of the Open Era, but those are separate milestones: 1922 concerned the Challenge Round, while 1968 ended the ban on professional players.