This cathedral exists because a duke demolished another one. At the end of the fifteenth century Pirro del Balzo, lord of Venosa, obtained the bishop's permission to pull down the old cathedral in order to build his castle there, on what was the weakest point of the city; in exchange he undertook to build a new one. The castle went up quickly, the church much less so.
What to see
Work began in 1470 and ended only in 1502, more than thirty years later; the consecration came later still. The building is Renaissance, with three aisles, its doorway and chapels of that period, and it stands in the centre of a town that at the same moment was being wholly redrawn by the same patron.
The bell tower was the longest part: begun more than a century after the church, at a bishop's order, taken up later by another and finished only in 1714. It has a square base carrying two octagonal bodies and finally a pyramidal spire, and being so tall it can be seen from the whole plain around.
Visiting
The co-cathedral is in piazza Castello, facing the castle that took the place of the earlier church; free entry, with hours tied to services. Half an hour.
Our editors' tip
Look at the bell tower from the bottom up: it changes style as it rises, because it was built in three goes over two centuries. Whoever laid the first stone never saw the second storey, and whoever finished it had known none of those who began it. It is a building site that outlasted three generations of patrons.