Aquileia (Flemish Aquilee, German Aquileja or Agley or Aglar (n), Slovene Oglej) is a city with 3359 inhabitants (as of December 31, 2015) in the Italian province of Udine. She was a big city of the Roman Empire. The remains of the Roman city can be visited in the open air and in two museums. In the medieval cathedral is the most important early Christian floor mosaic of Italy from the beginning of the 4th century.