The twin churches were built on the orders of Pope Alexander VII after his predecessors had constructed the Piazza del Popolo.
The first architect was Carlo Rainaldi, and work was continued by Bernini and Carlo Fontana.
At first it seems identical to its sister church, but there are differences.
Both have a portico with a classical tympanon, and are covered by a dome with fish-scale tiles.
The church has an elliptical plan and a dodecagonal dome.
The bell tower is good example of the Baroque style.