On December 4, 1154, the only English Pope in the whole history of the Catholic Church was elected, from 1154 to 1159.
His birth name was Nicholas Breakspear; he was an English priest of the Roman Catholic Church and as the 170th Pope he took the name of Adrian IV.
He succeeded Pope Anastasius IV, who died the previous day.
Cardinal Breakspear – made Bishop of Albano in 1146 — was the most favorable candidate; he was also the papal legate to Scandinavia.
He at once tried to bring down Arnold of Brescia, the leader of the anti-papal faction in Rome. Disorder in the city led to the murder of a cardinal.
Adrian, shortly before Palm Sunday 1155, took the step of putting Rome under interdict. The Senate (City Council of Rome) then exiled Arnold.
A proposed alliance with the Eastern Byzantine Empire came to nothing.
Adrian signed a Papal Bull (official letter) urging King Henry II of England to invade Ireland and bring the Celtic Christian church into the Roman system.
Pope Adrian was involved in Italian and European political disputes.
A dispute with Frederick I, Holy Roman Emperor was happening when Adrian died in 1159.