The hills surrounding the current location of Como have been inhabited, since at least the Bronze Age, by a Celtic tribe known as the Orobii. Remains of settlements are still present on the wood covered hills to the South West of town.
Around the 1st century BC, the territory became subject to the Romans. The town center was situated on the nearby hills, but it was then moved to its current location by order of Julius Caesar, who had the swamp near the southern tip of the lake drained and laid the plan of the walled city in the typical Roman grid of perpendicular streets. The newly founded town was named Novum Comum and had the status of municipium.
In 774, the town surrendered to invading Franks led by Charlemagne, and became a center of commercial exchange.
In 1127, Como lost a decade-long war with the nearby town of Milan. A few decades later, with the help of Frederick Barbarossa, the Comaschi could avenge their defeat when Milan was destroyed in 1162. Frederick promoted the construction of several defensive towers around the city limits, of which only one, the Baradello, remains.
Subsequently, the history of Como followed that of the Ducato di Milano, through the French invasion and the Spanish domination, until 1714, when the territory was taken by the Austrians. Napoleon descended into Lombardy in 1796 and ruled it until 1815, when the Austrian rule was resumed after the Congress of Vienna. Finally in 1859, with the arrival of Giuseppe Garibaldi, the town was freed from the Austrians and it became part of the newly formed Kingdom of Italy under the House of Savoy.
At the end of World War II, after passing through Como on his escape towards Switzerland, Benito Mussolini was taken prisoner and then shot by partisans in Giulino di Mezzegra, a small town on the north shores of Como Lake.
In 2010, a motion by members of the nationalist Swiss People's Party (SVP) has been submitted to the Swiss parliament requesting the
