This work represents a synthesis of the information available on the urban centres of the Roman province of Lusitania. The purpose of the study is to identify the most important cities of Lusitania, using evidence provided by historical sources, epigraphic finds, and the archaeological record. According to Roman historical sources, many of the major cities of modern Portugal and Spain had already been established by the end of the third century AD. However, these sources do not present a clear chronological portrait of the development of many of these cities from indigenous settlements to important components of the Roman administration of the province of Lusitania. While a thorough discussion of this process lies well beyond the bounds of the current project, this study does represent the first synthesis of the historical, epigraphic, and archaeological evidence for the earliest imperial Roman presence at the cities of Lusitania.