All the key facts and trending topics as the doubles semifinals get under way at the third Slam of the year.
WTA Staff

Learning

The only past Wimbledon champions remaining in the women's doubles draw are Kveta Peschke, who took the women's doubles title with Katarina Srebotnik in 2011, and Anna-Lena Groenefeld, mixed doubles champion in 2009 with Mark Knowles. Ekaterina Makarova and Elena Vesnina were the 2015 finalists, while Vesnina was also mixed doubles runner-up in 2011, with Mahesh Bhupathi, and 2012, with Leander Paes.

The second semifinal pits two teams who only teamed up in this year's grass season against each other. Prior to Wimbledon, Chan Hao-Ching and Monica Niculescu had only played - and lost - one match together, in Eastbourne; while Makoto Ninomiya and Renata Voracova had won one round in the ITF $100,000 Southsea tournament. All are bidding to reach their first ever Slam final.

Heather Watson and Henri Kontinen are the defending mixed doubles champions; Martina Hingis was their predecessor in 2015 (with Leander Paes). Hingis's partner this year, Jamie Murray, won the title alongside Jelena Jankovic in 2007.

Ekaterina Makarova and Elena Vesnina are tied at 1-1 in their head-to-head against Anna-Lena Groenefeld and Kveta Peschke. The German-Czech duo won 6-2, 6-4 in the semifinals of Toronto in 2013; the Russian pair were victorious 6-0, 6-2 in the second round of Miami this year.

María José Martínez Sánchez is the only woman remaining in the mixed doubles event who has yet to reach a Slam final. The Spaniard has made three semifinals in women's doubles - at Roland Garros in 2010 and 2012, and the 2012 US Open, all with Nuria Llagostera Vives.

Trending

Reading

The depth and openness of the women's field has made for some thrilling tennis at this year's Wimbledon. Tom Perrotta breaks down why a level playing field has meant there are no easy matches on the WTA any more for FiveThirtyEight.

Venus Williams's run to her second Grand Slam final of the year at the age of 37 while managing Sjögren's Syndrome is a remarkable feat. Louisa Thomas reminds us just how remarkable for The New Yorker.

Watching

Tomorrow's final will pit Venus Williams against Garbiñe Muguruza. Relive their dominant semifinal performances here.