The Washington Kastles — defending World Tennis Team champions, mind you — announced a big move today: both Williams sisters, Serena and Venus, will play for D.C.’s WTT outfit this summer. “The historic opportunity to have both Serena and Venus on our team is a thrill, both for the success of our team and for our fans, whose support has been so integral to our success,” said team owner Mark Ein. World number one Serena, who has been a Kastles mainstay since 2008, will be joined by fifth-ranked Venus, who will call Kastles Stadium home after a trade with Philadelphia.

As far as the breakdown goes, Serena will play four matches for the Kastles, and Venus three — one each at home. With Venus in the fold, the Kastles now boast two of the best tennis players of all time, in addition to cornering the WTT market on women’s Wimbledon contenders and boosting the current team roster’s total Grand Slam championships to a whopping 61. The Kastles will fill out the remainder of their roster on March 16.