He served for 26 years as the pope.
Pope Paul VI, 21 June 1963 to 6 August 1978. Between 1410-1415 there was an antipope John (Baldassare) XXIII. He, in his youth, had been a bona fide pirate! By taking the name John XXIII, Angelo...
Yes, he was the 23rd pope to take the name John.
Pope John XXIII was ordained pope on October 28th, 1958 The word ordained refers to priests. A bishop is installed, a pope is consecrated.
Pope Pius XII