Who protested the inequality of Wimbledon prize money in the 21st century?

Venus Williams protested the inequality of Wimbledon prize money in the 21st century. Her campaign helped persuade the tournament to pay its men’s and women’s singles champions equally from 2007 onward.

Williams began pressing the issue publicly around the 2005 Wimbledon Championships. Before the final that year, she addressed representatives of the Grand Slam tournaments about the pay gap. In 2006, she published an opinion piece in The Times arguing that Wimbledon’s policy undervalued the work of women players.

Wimbledon announced equal prize money in 2007, making it the last of tennis’s four major tournaments to do so. Williams then won the 2007 women’s singles title, defeating Marion Bartoli, and became the first woman to receive the same Wimbledon champion’s prize as the men’s winner.

Billie Jean King and other players had fought for equal pay decades earlier, so Williams was not the first tennis equality activist. The question specifically points to the 21st-century campaign focused on Wimbledon, for which Venus Williams is the canonical answer.