Markle and Williams first met in 2010 at the Super Bowl. They met again in 2014 and quickly became friends. Markle wrote on her now-defunct blog, The Tig, "We are both the same age, have a penchant for hot sauces, and adore fashion, but what connects us more than those things is perhaps our belief in exceeding expectations — our endless ambition."
Markle has been spotted courtside for Serena's matches at the US Open and Wimbledon and was also on hand to support her friend when she launched her clothing line at New York Fashion Week in 2017, while Serena frequently contributed to Markle's lifestyle site, The Tig. Williams and her husband, Alexis Ohanian, attended Markle and Harry's wedding.
Williams appeared on the first episode of Markle's "Archetypes" podcast, where they talked about motherhood, ambition, and their friendship. Markle asked Williams why she agreed to do the podcast, and the tennis legend responded, "I was gonna say because I love you and I believe in you! We've been friends for so long. I'm super loyal, to a fault, you know that."