 The Rossio became an important place in the city during the 13th and 14th centuries, when the population of the city expanded to the lower area surrounding the Lisbon Castle hill.The name "rossio" is roughly equivalent to the word "commons" in English, and refers to a commonly owned terrain.Around 1450, the Palace of Estaus, destined to house foreign dignitaries and noblemen visiting Lisbon, was built on the north side of the square.