The Evangelical Church of the Redeemer (Konstantinbasilika) in Trier (Augusta Treverorum) was originally a Roman palace auditorium. It was built as an audience hall for the Roman emperors who resided in the city in the 4th century. The naming after Constantine the Great as the Constantine Basilica reminds of this time and purpose. The name of the building as a basilica comes from the local history researcher Johannes Steiner in the 19th century, who took it from a late antique eulogy for the emperor Constantine. From today's perspective, it is unsuitable because it does not correspond to the type of building of a basilica, but to that of a hall church. The honorary Catholic title of basilica does not apply either, because the building was never a Catholic church.
In the early Middle Ages, the burned-out ruins came into the possession of the Trier bishops. They converted this into a castle-like property. In 1614 the south and east walls were torn down and the rest was integrated into the new bishop's residence, the Electoral Palace. The church-like building was restored between 1844 and 1856, consecrated on September 28, 1856 and handed over to the evangelical parish, which has been using it as a church since then. On August 14, 1944, the basilica was badly damaged by an American air raid and burned down completely. The reconstruction took place in the 1950s. The design of the interior was reduced to stone-faced exterior walls and a wooden coffered ceiling.
Since 1986 the Constantine Basilica has been part of the UNESCO World Heritage “Roman Monuments, Cathedral and Church of Our Lady in Trier”. It is also a protected cultural asset under the Hague Convention. The apse in the north, the west wall, remains of walls from previous buildings below the present-day floor and remains of Roman exterior paintings on the west and north facades have been preserved in the Roman building fabric. Wikipedia