Sad news for the Gates family. In a blog post on Sept. 15, Bill Gates revealed that his father, Bill Gates Sr., passed away peacefully at his home, surrounded by family. “We will miss him more than we can express right now,” he wrote. “We are feeling grief but also gratitude. My dad’s passing was not unexpected — he was 94 years old and his health had been declining — so we have all had a long time to reflect on just how lucky we are to have had this amazing man in our lives for so many years.” Bill Gates Sr. is survived by Bill and his two sisters, Libby and Kristianne Gates. And while Bill Gates is a household name, we’re curious about the other Gates siblings.