Michael Reagan, the eldest son of former U.S. President Ronald Reagan, has died at the age of 80. The Ronald Reagan Presidential Foundation and Institute announced his death, remembering him as a "steadfast guardian of his father's legacy." Reagan, a conservative commentator and radio host, was adopted by Ronald Reagan and his first wife, Jane Wyman. He also pursued acting and dedicated much of his public life to promoting his father's ideals and working with various charities. His cause of death was not immediately announced, but his family stated he died surrounded by loved ones.