On the basis of archeological and architectonic studies, personal judgements and his acquaintance with the topography of the city of Senj and, in addition, taking into consideration, the geography, natural setting, network of roads and other specificities of the region, the author traces its palaeogenesis (the process of the rise and development of a settlement from the earliest date to its becoming a full urban center) and gives special attention to the question of the urban development of Antique Senia. The author considers that the first fortification rose on the hill of Kuk and was encircled with walls having a distinctive spatial division. Owing to its favourable geographical position (a good port and the starting point of the shortest land route which, through the Vratnik pass, leads to the interior of the continent) the fortification, prehistoric Senia, became a civitas - the administrative, religious, economic and strategic center of its territory. The settlement grew under the fortification and a market place in the direction of the bay. From the 2nd century BC onward, primarily due to commercial concerns but also owing to political, military and other reasons, a process of infiltration of the Italiot population got under way. By the 1st century BC, because of the Italiot settlers and the romanized native privilidged population, Senia became the focal point for the romanization of the coastal region under the Velebit mountain range and a secure stronghold for military campaigns waged against the nearby Japodas living on the other side of Velebit. It is assumed that the urban development of antique Senia began during this period; during the time of Augustus it was given a municipal status and became a Roman city. The operative coast of the bay and its important network of roads are the bases for its urban shape; according to the rules of Roman city construction, it developed following a planned orthogonal scheme(with possible deviations because of the terrain) in the direction of NW-SE (decuman) and NE-SW (cardo). On the basis of archeological findings and architectonis studies, it is believed that the center of Roman Senia was located on or near today's wide thoroughfare (East of St. Mary's cathedral). Necropolises verified by documents and findings of antique architecture approximately outline the urban area of ancient Senia which was in area greater than Medieval Senia. During the great migrations the city was razed to the ground and burned. The city of Senj grew, spontaneously and organically, upon a part of the ancient city. In spite of numerous violent and non-violent changes during its turbulent past, it has retained its typically Medieval appearance, with traces of its antique tradition, to this very day.
