Pope Nicholas V, born Tommaso Parentucelli, was head of the Catholic Church and ruler of the Papal States from 6 March 1447 until his death, in March 1455. Pope Eugene IV made him a cardinal in 1446 after successful trips to Italy and Germany, and when Eugene died the next year, Parentucelli was elected in his place. He took his name Nicholas in memory of his obligations to Niccolò Albergati.

Niccolò Albergati was an Italian Carthusian and a prelate of the Roman Catholic Church. He was appointed cardinal and served as a papal diplomat to France and England (1422–23) in addition to serving as the bishop of Bologna from 1417 until his death.