SEATTLE — William H. Gates II, a lawyer and philanthropist best known as the father of Microsoft co-founder Bill Gates, has died at 94.

Gates died peacefully Monday at his beach home in Washington state from Alzheimer’s disease, the family announced Tuesday.

In an obituary the family credited the patriarch with a “deep commitment to social and economic equity,” noting that he was responsible for the Bill & Melinda Gates Foundation’s first efforts to improve global health as well as his advocacy for progressive taxation, especially unsuccessful efforts to pass a state income tax on the wealthy in Washington.

Gates Sr. was a towering figure by reputation and in person — he stood 6-foot-7 tall — and his counsel was often sought. Former Starbucks Chairman Howard Schultz has said that when he was struggling to raise the money to buy the six-store coffee chain in 1987, Gates Sr. stepped in to rescue him from a rival buyer — not only by investing, but by personally taking Schultz to visit the rival, demanding as he loomed over the rival’s desk: “You are going to stand down and this kid is going to realize his dream. Do you understand me?”