The Bonn Minster (Bonner Münster) is one of Germany's oldest churches, having been built between the 11th and 13th centuries. At one point the church served as the cathedral for the Archbishopric of Cologne.
Castra Bonnensia was a fortress on the site of current Bonn built by the Romans in the 1st century AD. It survived the breakup of the Roman Empire as a civilian settlement, and in the 9th century it became the Frankish town of Bonnburg.
Around 235 AD, two Christian Roman soldiers stationed in Castra Bonnensia, Cassius and Florentius, were martyred for their faith. Tradition has it that a small memorial shrine was built over their graves in the 4th century by St. Helen, mother of Constantine. There is no surviving evidence of this first structure, but archaeological excavations have shown that the basilica stands on the site of a Roman temple and necropolis.
The original memorial hall was expanded into a larger church in the 6th and 7th centuries, and many people were buried near the martyrs inside and outside the building. Further extensions were carried out in the 8th century.
Around 1050 the church was demolished and construction began on the present Romanesque building, which dates from the 11th to 13th centuries. By the end of this period Bonn had grown in importance, becoming the capital of the Electorate and Archbishopric of Cologne, which was then a sovereign state. The new basilica appeared in the city's coat of arms. In 1643, Cassius and Florentius were officially declared the patron saints of the city of Bonn.
The basilica suffered significant damage in 1583-89, 1689, and in World War II, but each time it was fully restored. In 1956, the Bonner Münster was granted the status of Papal Minor Basilica.References:
Sirmione castle was built near the end of the 12th century as part of a defensive network surrounding Verona. The castle was maintained and extended first as part of the Veronese protection against their rivals in Milan and later under the control of the Venetian inland empire. The massive fortress is totally surrounded by water and has an inner porch which houses a Roman and Medieval lapidary. From the drawbridge, a staircase leads to the walkways above the walls, providing a marvellous view of the harbour that once sheltered the Scaliger fleet. The doors were fitted with a variety of locking systems, including a drawbridge for horses, carriages and pedestrians, a metal grate and, more recently, double hinged doors. Venice conquered Sirmione in 1405, immediately adopting provisions to render the fortress even more secure, fortifying its outer walls and widening the harbour.
Thanks to its strategical geographical location as a border outpost, Sirmione became a crucial defence and control garrison for the ruling nobles, retaining this function until the 16th century, when its role was taken up by Peschiera del Garda.