His Holiness Pope John XVII, né Sicco (died November 6, 1003), was a native of Rome who succeeded Silvester II as pope on June 13, 1003, but died less than five months later. Before entering the priesthood, Sicco had been married and had three sons who also became bishops.

Pope John was nominated to the papacy by John Crescentius , a Roman noble who held power in the city in opposition to Otto III, Holy Roman Emperor. John XVII's successor, Pope John XVIII, was also selected by Crescentius.

The previous legitimate Pope John was John XV. "John XVI" was an anti-Pope, and his regnal number XVI should have been reused. But this did not occur, and the sequencing has never been corrected. Also, since there was never a Pope John XX at all, this means there have only been 21 legitimate popes named John, not 23 as the regnal number of Pope John XXIII would suggest.

References

• Pope John XVII from the Catholic Encyclopedia