The Säve Church was erected in the early 13th century. It was first known as St. Olaf Church, after the saintly king Olaf II of Norway. The nave has a barrel vault, built in 1696. In 1704, the ceiling was covered with paintings by German artist Christian von Schönfeldt. In 1729, a cupola was built over the choir, painted by Johan Ross. The paintings depict scenes from both the New and the Old Testament. The porch was built in 1746, and the wooden tower above it was erected in 1750. The choir got its stained glass window in 1902. In 1945, the brick roof of the nave was replaced with slate.
References:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.