The original castle on the Marienberg, a hill which was first settled in the late Bronze Age, was probably a small fort built early in the 8th century by the Franconian-Thuringian dukes, together with a church which in 741 became the first church of the Würzburg bishops. From 1200 an unusually large castle was built, which was extended during the late Middle Ages and the Renaissance.
Following the storming of the castle in 1631 by the Swedes, Prince-Bishop Johann Philipp von Schönborn built a circle of massive bastions to protect the Marienberg. In 1945 the fortress was almost completely burned out, and its reconstruction was only completed in 1990.
On the first floor of the Princes' Building Museum (administered by the Bavarian Palace Department), is the Bibra Apartment with valuable furniture, tapestries and paintings, the Princes' Hall with early Gothic arcatures and the large Echtersche family tapestry, as well as a treasury and vestment chamber from the era of the prince-bishops. On the second floor is the Main-Franconian Museum documenting the history of the fortress and town.
The 1,300 m2 Princes' Garden is accessible from the castle courtyard: it was reconstructed in 1937-38 on the basis of plans dating from the early 18th century.
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.