The church of Sant’Andrea delle Fratte takes its name from its ancient location which until about 1880 was rural enough to be called Sant’Andrea in Hortis.
The construction of the present church began around 1604 following the project of Gaspare Guerra, the work was stopped several times and Borromini was even commissioned to build it. From 1653 to the year of his death in 1667 he followed the work and changed the project by realizing one of his ingenious architectures by putting his hand to the whole high part of the church: the apse, the bell tower and the drum of the dome that, seen from above, form the classic cross of St. Andrew.
