Catholic Encyclopedia (1913)/Pope John XVII (XVIII)
Date of birth unknown; d. 6 Nov., 1003. When Sylvester II died on 12 May, 1003, there was no actual authority in Rome which could curb the nobles. Thus the faction of Crescentius again won the upper hand, and John Crescentius, son of the patricius whom Otto III had defeated and put to death, seized the authority for himself. The three following popes were indebted to him for their elevation, and were made to feel his supremacy. A Roman, Sicco, was first elected, and consecrated on 13 June as John XVII, but died on 6 November. Before taking orders he had been married, and had three sons who also became ecclesiastics. Concerning his activities during the few months of his pontificate nothing has come down to us.
Liber Pontif., ed. DUCHESNE, II, 265; JAFFÉ, Regesta, I (2nd ed.), 501; LANGEN, Gesch. der röm. Kirche, III, 401.