Trier is Germany’s oldest city, dating from Roman times even though Worms fiercely vies for the title of "Oldest City in Germany, also.
In 2009, Trier celebrated its 2025th birthday and its uninterrupted tradition of urban living since 17 BC.
The founding date is derived from the age of the wooden pilings of the first Moselle bridge found in the mud of the river.
Through a comparison of the annual growth rings (dendrochronology), the date when the trees for the pilings were felled was determined to be 17 BC.

In its eventful history, Trier has served, among other purposes, as the seat of government for the Western Roman Empire;
in the Middle Ages, it received the name “holy city”; it has survived many wars as a border city between Germany and France,
and is today a university city in the heart of Europe. (Trier Tourist Information)