Pope Adrian I was 95 years old when he passed away. That makes him the oldest Pope we’ve ever had. Runner up goes to Pope Leo XIII,who was 93 when he died in 1903. Pope Adrian reigned for 23 years,which was the longest time in office until Pope Pius VI reigned for 24 years from 1775 to 1799. Popes Pius IX,Leo XIII,and John Paul II would go on to be the only other Popes who served longer. Pope Adrian busied his time with diplomatic relations with both the Lombards and the Franks,mostly favoring the Franks. King Charlemagne of the Franks was particularly close to the Pope and considered Adrian to be like a father to him. In fact,Charlemagne openly wept at Adrian’s funeral and later lovingly dedicated a epitaph to him which can still be seen at the door to St.Peter’s basilica.