The Battle between the Horatii and the Curiatii

Livy sets this fight in the reign of Tullus Hostilius, Rome's third king, when Rome and Alba Longa, the older town its founders had come from, stood on the edge of war. To settle the quarrel without a full battle, each side chose three brothers to fight for it. Two of the Roman Horatii fell. The third ran, and as the three wounded Curiatii of Alba Longa strung out behind him, he turned and killed them one at a time. Alba Longa submitted to Rome.

Giuseppe Cesari painted the duel in 1612 and 1613, the third scene of the cycle on these walls, and the hall takes its name from it.

More than three centuries later the room saw a very different settlement between neighbours. At six in the evening on 25 March 1957, representatives of Belgium, France, West Germany, Italy, Luxembourg and the Netherlands met here to sign the Treaties of Rome, which created the European Economic Community and Euratom. On 29 October 2004 the leaders of the European Union came back to the same hall to sign the treaty for a European constitution, at a table set beneath Alessandro Algardi's bronze statue of Pope Innocent X.