John XVII

John, called Sicco, was a Roman from the Biberatica quarter near Trajan's forum, a married man before he was ordained, with three sons who became clerics, and he was elected on 16 May 1003, four days after Sylvester II died, by the will of John Crescentius, the patrician who had governed Rome since Otto III's death and would choose the next two popes as well. He reigned until 6 November 1003, a little under six months. No act of his survives with certainty; a letter authorizing missionaries to the Slavs that some attribute to him belongs more probably to his successor. He was buried in the Lateran.

He is the first of the three popes of John Crescentius, who held the city from 1003 to 1012 by keeping the emperor Henry II out of it and the pope inside the Lateran, and the shortest-lived. His successor John XVIII, another Crescentian choice, lasted six years; Sergius IV, the third, died a week after the patrician. John XVII is the point at which the Roman papacy of the Crescentii can be seen most plainly for what it was, an office filled by a layman with a candidate and a date, and his six months are the whole of his history.