years ago, the dense layer of much younger debris obscures Palaeolithic and Neolithic sites. Evidence of stone tools, pottery, and stone weapons attest to about 10,000 years of human presence. Several excavations support the view that Rome grew from pastoral settlements on the Palatine Hill built above the area of the future Roman Forum. Between the end of the Bronze Age and the beginning of the Iron Age, each hill between the sea and the Capitol was topped by a village (on the Capitol Hill, a village is attested since the end of the 14th century BC). However, none of them yet had an urban quality. Nowadays, there is a wide consensus that the city developed gradually through the aggregation ("synoecism") of several villages around the largest one, placed above the Palatine. This aggregation was facilitated by the increase of agricultural productivity above the subsistence level, which also allowed the establishment of secondary and tertiary activities. These, in turn, boosted the development of trade with the Greek colonies of southern Italy (mainly Ischia and Cumae). These developments, which according to archaeological evidence took place during the mid-eighth century BC, can be considered as the "birth" of the city. Despite recent excavations at the Palatine hill, the view that Rome was founded deliberately in the middle of the eighth century BC, as the legend of Romulus suggests, remains a fringe hypothesis. Legend of the founding of Rome Traditional stories handed down by the ancient Romans themselves explain the earliest history of their city in terms of legend and myth. The most familiar of these myths, and perhaps the most famous of all Roman myths, is the story of Romulus and Remus, the twins who were suckled by a she-wolf. They decided to build a city, but after an argument, Romulus killed his brother and the city took his name. According to the Roman annalists, this happened on 21 April 753 BC. This legend had to be reconciled with a dual tradition, set earlier in time, that had the Trojan refugee Aeneas escape to Italy and found the line of Romans through his son Iulus, the namesake of the Julio-Claudian dynasty. This was accomplished by the Roman poet Virgil in the first century BC. In addition, Strabo mentions an older story, that the city was an Arcadian colony founded by Evander. Strabo also writes that Lucius Coelius Antipater believed that Rome was