 McCain's father and paternal grandfather eventually became Navy admirals, and were the first father–son pair to achieve four-star admiral rank.His grandfather, Admiral John S. "Slew" McCain, Sr. (1884–1945), was a pioneer of aircraft carrier operations who in 1942 commanded all land-based air operations in support of the Guadalcanal Campaign, and who ultimately in 1944–1945 aggressively led the Fast Carrier Task Force in the Pacific Ocean theater of World War II.His operations off the Philippines and Okinawa, and air strikes against Formosa and the Japanese home islands, caused tremendous destruction of Japanese naval and air forces in the closing period of the war.