Rheineck Castle was probably built in the 12th century. The sources name the count palatine Otto I of Salm as the founder. After his death, King Konrad III seized his estate and transferred it to his brother-in-law, Count Herman of Stahleck. This endeavour resulted in a bitter fight for the County Palatine of the Rhine - a conflict that culminated in the complete destruction of Rheineck Castle by the troops of the King in 1151. Rheineck Castle was rebuilt by the Archbishopric of Cologne by 1164 at the latest but did not, however, withstand the Palatine War of Succession in the 17th century. The Prussian politician von Bethmann-Hollweg inherited the ruin in 1832 and had the main building reconstructed together with the castle chapel. The latter represents a special feature, with its eight-sided design, which is reminiscent of the Carolingian Octagon of Aachen Cathedral. Today, the Castle is in private ownership and cannot be visited.
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.