This book focuses upon the colony Aelia Capitolina founded by Hadrian on the ruins of Jerusalem, within the general context of his politics of Empire and in particular that of the new developments which had taken place in Judaea since the beginning of his reign. Our knowledge has recently been greatly enhanced thanks to the archaeological excavations carried out in and around Jerusalem. Those of the Shu'afat neighbourhood in north-eastern Jerusalem, 4 km north of the ancient Jerusalem, enlighten us as to what may have been the actual significance of the establishment of the new colony for the Judean Jews, while the excavations carried out in the Old City of Jerusalem allow us to date both the official foundation, presumably two years before the outbreak of the Bar Kokhba War, and the very beginning of the preparatory works, about a decade earlier. These data, in turn, enable us to infer that the founding of the new colony may be seen as one of the causes leading up to the Bar Kokhba War that was to break out a few years later.