Philip King (1927-2015): This Philip King was a British playwright, known for his works like "Sleuth" and "The Two of Us." He passed away on October 18, 2015, at the age of 88.
Philip King (1940-present): This Philip King is an American playwright and screenwriter. He is still alive.
Therefore, the Philip King you're likely referring to died on October 18, 2015.