Origins (until 650)
Although there is some evidence of earlier inhabitation in the region of Utrecht, dating back to the Stone Age (app. 2200 BCE) and settling in the Bronze Age (app. 1800–800 BCE), the founding date of the city is usually related to the construction of a Romanfortification (castellum), probably built in around 50 CE. These fortresses were designed to house a cohort of about 500 Roman soldiers. Near the fort a settlement would grow housing artisans, traders and soldiers' wives and children. A line of such fortresses was built after the Roman emperor Claudius decided the empire should not expand further north. To consolidate the border the limes Germanicusdefense line was constructed. This line was located at the borders of the main branch of the river Rhine, which at that time flowed through a more northern bed compared to today, along what is now the Kromme Rijn.
In Roman times, the name of the Utrecht fortress was simply Traiectum denoting its location at a possibility to cross the Rhine. Traiectum became Dutch Trecht. The U comes from Old Dutch "uut" meaning downriver. It was added to distinguish from the other Tricht, Maas-tricht. In 11th century official documents it was then Latinized as Ultra Traiectum. Around the year 200, the wooden walls of the fortification were replaced by sturdier tuff stone walls, remnants of which are still to be found below the buildings around Dom Square.
From the middle of the 3rd century Germanic tribes regularly invaded the Roman territories. Around 275 the Romans could no longer maintain the northern border and Utrecht was abandoned. Little is known about the next period 270–650. Utrecht is first spoken of again centuries after the Romans left. Under the influence of the growing realms of the Franks a church was build in the 7th century within the walls of the Roman fortress during Dagobert I's reign. In ongoing border conflicts with the Frisians
