The church in its current form was commissioned by Pope Hadrian I around the year 780, and built on top of the remains of a 5th-century structure and was designed to house the bones of Saint Praxedes (Italian: S. Prassede) and Saint Pudentiana (Italian: S. Pudenziana), the daughters of Saint Pudens, traditionally St. Peter's first Christian convert in Rome. The two female saints were murdered for providing Christian burial for early martyrs in defiance of Roman law. The basilica was enlarged and decorated by Pope Paschal I in c. 822.
Pope Paschal, who reigned 817-824, was at the forefront of the Carolingian Renaissance started and advocated by the emperor Charlemagne. They desired to get back to the foundations of Christianity theologically and artistically. Paschal, thus, began two, linked, ambitious programs: the recovery of martyrs' bones from the catacombs of Rome and an almost unprecedented church building campaign. Paschal dug up numerous skeletons and transplanted them to this church. The Titulus S. Praxedis was established by Pope Evaristus, around 112.
The church provided the inspiration for Robert Browning's poem "The Bishop Orders His Tomb at Saint Praxed's Church."
Interior of Santa Prassede
The main altarpiece is a canvas of St Praxedes Gathering the Blood of the Martyrs (c. 1730-35) by Domenico Muratori.
The most famous element of the church is the mosaic decorative program. Paschal hired a team of professional mosaicists to complete the work in the apse, the apsidal arch, and the triumphal arch. In the apse, Jesus is in the center, flanked by Sts. Peter and Paul who present Prassede and Pudenziana to God. On the far left is Paschal, with the square halo of the living, presenting a model of the church as an offering to Jesus. Below runs an inscription of Paschal's, hoping that this offering will be sufficient to secure his place in heaven.
On the apsidal arch are twelve men on each side, holding wreaths of victory, welcoming the souls into heaven. Above them are symbols of the four Gospel writers: Mark, the lion; Matthew, the man; Luke, the bull; and John, the eagle, as they surround a lamb on a throne, a symbol of Christ's eventual return to Earth.
Though those mosaics as well as those in the Saint Zeno chapel, a funerary chapel Paschal built for his mother, Theodora, are the best-known aspects of the church, an intriguing and relatively hidden aspect are ancient frescoes. Ascending a spiral staircase, one enters a small room, covered in scaffolding. However, on the wall is a fresco cycle dating most likely from the 8th century. The frescoes depict probably the life-cycle of the name saint of the church, Praxedes.
Among these legendary relics retrieved by Helena, which included pieces of the True Cross (now housed in the church of Santa Croce in Gerusalemme, also in Rome) and wood from the Jesus' crib, was the segment of the pillar now housed in Santa Prassede. The authenticity of these relics, including the Santa Prassede pillar, is disputed by historians and Christians alike, due to lack of forensic evidence and proliferation of fake relics during the Middle Ages.