Petra in modern southern Jordan is universally known as one of the most frequented tourist sites in the Near East, inscribed on the UNESCO world heritage list. Modern visitors are attracted by the romantic aspect of the rock-cut tomb facades, heavily contrasting in their baroque style with the rocky desert surrounding it. These monuments were the result of the long time presence of the Arab tribe of the Nabataeans who made Petra their capital when they became, at least partially, sedentarised during the Hellenistic period. How exactly this process of sedentarisation happened, how the site of Petra changed from a temporary dwelling place of a small Bedouin tribe to one of the blinking capitals of the ancient Near East that attracted - as it is the case today - visitors from all over the world, was the subject of a three years research program. At the end of that program, an international conference, held in Berlin in December 2011, brought together several dozens of scholars from all over the world in order to pinpoint the state of research on the Formation of the Nabataean capital. The contributions of the present volume focus on questions related to the natural environment of the site, on the geology and geography as well as on architecture, small finds and social dynamics, probably the clue for a better understanding of the functioning of the Nabataean kingdom and its capital Petra.