In front of the church stands a column, and it is the reason for the name. Tradition holds that saint Alexander, patron of Bergamo, was killed there; in fact it is almost certainly a Roman funerary monument, dedicated to a certain Crotacius and perhaps once topped by a pagan divinity. It appears in the documents already in 1133, under that name.
What to see
The column you see today was reassembled in 1618 using Roman fragments, so it is an ancient piece put back together in the modern age. The basilica behind it has origins just as distant: it collapsed in the fifteenth century, was rebuilt and consecrated, then remade again in the eighteenth according to Counter-Reformation criteria.
That remodelling erased important parts of the earlier building: of the chapel designed in the sixteenth century by Pietro Isabello only the stone pillars remain, absorbed into the new walls. It is the ordinary fate of Italian churches, which are rebuilt over themselves, each time cancelling something.
Visiting
The basilica is in via Sant'Alessandro, in the lower town, ten minutes on foot from the funicular to the upper town; free entry with hours tied to services. Half an hour.
Our editors' tip
Look at the column before going in, and count the layers: a pagan Roman tomb, then the site of a Christian martyrdom, then the name of a street, then the name of a church, and finally a seventeenth-century reassembly made of ancient pieces. One object, five different uses, and all of them still legible.