Williams' first reported struggles with her back came against Li Na in the semifinals of Cincinnati last August. She ended up losing the match in three sets and afterwards talked about the pain starting in the warm-up, and that it grew worse and worse as the match went on. Li went on to win the title.
This is the fourth tournament Williams has withdrawn from since then due to her back, fifth if you count her mid-tournament withdrawal in Miami this year, and sixth if you count the French Open doubles.
"Unfortunately, I will not be able to participate in Wimbledon this year," Williams announced on her Facebook page on Tuesday. "I am extremely disappointed as I have always loved The Championships, but I need to take time to let my back heal. I look forward to returning to the courts as soon as possible, with my goal being to return to Mylan World Team Tennis on July 8th in Washington DC. Many thanks to my fans for the love and support and I will be seeing you very soon back on the courts."
Williams has reached the Wimbledon final an amazing eight times in 16 previous appearances, winning the title five times (2000, 2001, 2005, 2007 and 2008) and finishing runner-up three times (2002, 2003 and 2009, falling to Serena Williams in each of those finals). Additionally she is a five-time doubles champion, all five of those titles coming with Serena Williams (2000, 2002, 2003, 2009 and 2012).
Williams has withdrawn from the other three majors before, but this is the first time at Wimbledon.