Trier is a historic city in west central Germany and the country's oldest city. Legend has it that in 2000 BC, the Assyrians established a colony here. The Roman colony of Augusta Treverorum (Trier) was founded by Augustus in 16 BC. Trier became the favored residence of several Roman emperors, including Constantine the Great, the first Christian emperor. The cathedral Constantine built in Tier in 326 AD is Germany's oldest. After destruction by Germanic tribes in the 5th century, the great city of Trier became a small town. Trier's market square (Hauptmarket) is one of the nicest in Germany. Catholic pilgrims still come to Trier in large numbers to honor the relic of the Holy Robe at the Dom St. Peter and the tomb of St. Matthias in the Benedictine church named for him.