Twitter co-founder Evan Williams is leaving the company’s board, according to a document filed with the Securities and Exchange Commission on Friday.
Williams, who formerly served as CEO of Twitter (TWTR) for two years until 2010, will step down at the end of February.
“It’s been an incredible 13 years, and I’m proud of what Twitter has accomplished during my time with the company,” Williams said in a statement published in the filing. “I will continue rooting for the team as I focus my time on other projects.”
On Twitter, Williams tweeted his thanks to his co-founders, Jack Dorsey and Biz Stone.
“Thank you, @jack and @biz for starting this crazy company with me—and continuing to make it better and better,” he tweeted. “And to my fellow board members, new and old—some of the most thoughtful people I’ve ever known.”
Dorsey tweeted back, “I appreciate you, Ev!” He said Williams was the reason he originally joined Odeo, the company where they first came up with the idea for Twitter, and that they miss Williams’ voice in their board conversations.
Williams also thanked Twitter’s nearly 4,000 employees and said he would continue to “root for the team.”
In April 2017, Williams started selling off shares in Twitter as the company was struggling to grow subscribers. He said he planned to use the money from the sale to invest in startups as well as make political and philanthropic donations. As of May 2018, Williams owned 3.86% of Twitter’s shares.
Williams is also the founder of the blogging platform Medium.