A church at the site was founded by the 8th century. The church was recorded as a
diaconia (a centre for helping the poor and the sick) at the end of the pontificate of
Pope Gregory II (715-731). It is mentioned in some documents dating from the 10th and 11th centuries, where this church is called
in platana (between the
plane trees) referring to the tree planted in the garden of the martyr Eustace. However, tradition holds that the emperor
Constantine I had previously built an
oratory here. This church was called "ad Pantheon in regione nona e iuxta templum Agrippae" (at the Pantheon in the ninth
rione and next to the temple of Agrippa"). The church was restored and had a new
campanile added at the end of the 12th century during the pontificate of
Celestine III (1191–1198), who also deposited the putative relics of Eustace and his family in the church. In the 16th century, it was a favored praying-place for St
Philip Neri. In the 17th and 18th centuries it was almost completely rebuilt, with only the campanile remaining from the old structure. The new design, in the Roman
Baroque style, was produced by several architects : Cesare Corvara and Giovanni Battista Contini (1641–1723), who added chapels and the
portico, Antonio Canevari (1681–1750),
Nicola Salvi (1697–1751) and finally, from 1728, Giovanni Domenico Navone. The new high altar, in bronze and
polychrome marble, was added by Nicola Salvi in 1739 and in 1749
Ferdinando Fuga put a
baldachin over it. The choir and the sacristy were designed by Canevari and built by Giovanni Moscati. ==Façade==