The first mention of Innsbruck dates back to the name Oeni Pontum or Oeni Pons which is Latin for bridge (pons) over the Inn (Oenus), which was an important crossing point over the Inn river. The Counts of Andechs acquired the town in 1180. In 1248 the town passed into the hands of the Counts of Tyrol. The city's arms show a bird's-eye view of the Inn bridge, a design used since 1267. The route over the Brenner Pass was then a major transport and communications link between the north and the south of Europe, and the easiest route across the Alps. It was part of the Via Imperii, a medieval imperial road under special protection of the king. The revenues generated by serving as a transit station on this route enabled the city to flourish.