Monday was a rather sad day for Seattle sports fans & the tech world. Paul Allen, the man who resurrected sports in the Seattle area and co-founded Microsoft with Bill Gates in 1975, passed away at the age of 65 due to complications from cancer his family announced.

Allen had announced earlier this month that he had been diagnosed with non-Hodgkin’s lymphoma, a cancer that kills nearly 20,000 people a year. He had been treated for it back in 2009, but unfortunately it returned. “My team of doctors has begun treatment of the disease and I plan on fighting this aggressively,” Allen said in a statement earlier this month. “A lot has happened in medicine since I overcame this disease in 2009. My doctors are optimistic that I will see good results from the latest therapies, as am I.”

“My brother was a remarkable individual on every level. While most knew Paul Allen as a technologist and philanthropist, for us he was a much-loved brother and uncle, and an exceptional friend,” his sister said in the statement. She continued: “Paul’s family and friends were blessed to experience his wit, warmth, his generosity and deep concern. For all the demands on his schedule, there was always time for family and friends. At this time of loss and grief for us – and so many others – we are profoundly grateful for the care and concern he demonstrated every day.”

According to Forbes, Allen was the 44th richest person in the world with a net worth of $20.3 billion dollars. He owned both the Portland Trailblazers & Seattle Seahawks.

RIP to the computer legend.