Bregenz is situated on the eastern shore of the lake Bodensee (Lake Constance). On the site of a settlement of the Bronze Age, the Celtic tribe of the Brigantians founded a fortress. Strabon, a Greek geographer, mentions the place as Brigantium in 63 BC. The Romans conquered the fortress in 15 BC and built a garrison which soon became an important trading place. From about AD 450 the Germanic Alemanni began to migrate into the area. The local people were christianized by Irish monks, Columban and Gallus, at the beginning of the 7th century. from 500 to 1150, Bregenz belonged to the Ulrichs who also called themselves Counts of Bregenz. They were followed by the Counts of Montfort. The Habsburg Duke Siegismund bought one half of the town in 1451; the other half was bought by the Habsburgs in 1523. In the times of the Napoleonic Wars the town was part of Bavaria (1805–1814). In 1861 Bregenz became the seat of the provincial parliament (Landtag). Since 1919 it is the capital of the Austrian federal state of Vorarlberg.
The landmark of Bregenz is the Martinsturm [background centre right, barely visible]. The tower was built 1599–1602. Its 'onion' roof is the largest in central Europe. The chapel of St. Martin in the lower part of the tower dates back to 1361. Frescos of 1361/1362 and of 1420 were discovered in 1914.
The parish church St. Gallus [left] was built in the 14th and 15th century in Gothic style on prior Roman and Romanesque structures. It is believed to be the place where St. Gallus built a church. The interior was remodelled in Baroque style in 1737–1738.
Hohenbregenz castle [near left, no. 2749: top right; and right, no. 3483] is located southeast of Bregenz on the Gebhardsberg (598 m), the southern foothill of the Pfänder mountain. The castle was founded in the last quarter of the 11th century (before 1097) by the counts of Bregenz. The earliest written document mentioning the castle dates from 1209. In 1170 the castle came in possession of palsgrave Hugo of Tübingen (Hugo I as count of Montfort). In 1451 the upper part of the castle was sold to the Habsburgs, followed by the lower part of the castle in 1523. From then on, the castle served as the seat of Austrian bailiffs. In the eary 17th centur, the castle was enlarged to become a fortress. However, towards the end of the Thirty ears' War (1618–1648) the castle was conquered by Swedish troops who immediately blew up the fortress. The ruins then became home of eremites, and from 1670 onward the place became a pilgrimage site dedicated to Saint Gebhard (count Gebhard II of Bregenz, born 949; 979–995 bishop of Konstanz). The church built in this site was dedicated to St. George and St. Gebhard in 1723. This church burnt down in 1791 but was rebuilt already in the same year. A reliquiary of an arm of St. Gebhard was donated to the church in 1821 by the monks of Petershausen monastery, which had been founded by Gebhard prior to 983.