SEATTLE, Washington (ABC4) – After 27 years of marriage, Bill and Melinda Gates announced their decision to end their marriage Monday afternoon.

Gates, who co-founded Microsoft in 1975, made the announcement in a tweet Monday.

The tweet said, “After a great deal of thought and a lot of work on our relationship, we have made the decision to end out our marriage. Over the last 27 years, we have raised three incredible children and built a foundation that works all over the world to enable people to lead healthy, productive lives. We continue to share a belief in that mission and will continue our work together at the foundation, but we no longer believe we can grow together as a couple in this next phase of our lives. We ask for space and privacy for our family as we begin to navigate this new life.”

In 2000, Bill and Melinda Gates founded the “Bill and Melinda Gates Foundation,” which is a nonprofit foundation that addresses disease, poverty, and inequity around the world, according to the foundation’s website.

The foundation has spent $53.8 billion towards these causes since 2000.

Gates stepped down as CEO of Microsoft in 2000, and last year, announced his stepping down from Microsoft’s board in order to spend more time on the Bill and Melinda Gates Foundation.