Surrounded by the former palace of the Venetian ambassador to the Papal States, this venerable basilica stands almost in the shadow of the Capitoline Hill, the symbolic heart of ancient Rome. There are several layers of ruins beneath the current church, including some from the late empire that bear signs of Christian worship on this site before the construction of this church. Pope St. Mark was the founder of the first large house of Christian worship on this site in the mid 330s. Whether his gift consisted of the church itself or just the land on which it is built is unknown; archeological finds point to the construction of the first basilica on this site to sometime in the first half of the fourth century. This was replaced by another basilica on a somewhat higher level around the middle of the sixth century. Two features of this now lost structure are worthy of mention. One was the Byzantine influences in its sanctuary, these being a sign of Eastern influence on the Roman liturgy in general throughout this period. Another was a record being made during the iconoclastic controversies of this time, during which the abundance of sacred art present in this basilica was noted. This second basilica was in turn replaced under Pope Gregory IV in the second quarter of the ninth century, and it is this third basilica which, much renovated, still stands today. The two later churches kept the same dimensions as the first, the only difference being the heightened floor due to the rising ground level outside. The Venetian Pope Paul II undertook a renovation in the mid-fifteenth century, including the construction of the Renaissance loggia in front as a setting for papal blessings. This has a similar appearance to that which stood before the original St. Peter’s Basilica, also built in this period. The mid-fifteenth century palace adjoining the basilica, formerly a papal residence, was given by them to the Venetians for use as an embassy in 1564, likely because of the connection to St. Mark, the patron of the great seaport. The Venetian ambassador would finance a renovation of the church in the mid-seventeenth century. Yet another renovation a century later saw the interior of the basilica take on its current appearance, including the distinctive red columns along the nave. Restorations were undertaken in the 1840s and 1940s, this latter one restoring the crypt. This is noteworthy as being a good example of an annular crypt, so called because of its ring-like shape as it curves around the back of the apse. These were common features of churches built in the late first millennium, although many have been lost in the subsequent centuries.