Based on the spectacular development of North-Arabian archaeology and epigraphy in the last fifteen years,this paper aims to reappraise the sequence and chronology of political powers in north-west Arabia during the secondhalf of the 1st millennium BCE. To this end, it summarises the epigraphic and archaeological evidence from the sitesof the al-ʿUlā area (notably Dadān and Ḥegrā) and confronts it with the recently published data from the third mainarchaeological site in north-west Arabia: Taymāʾ. This review of the evidence not only supports an early dating of theLihyanite kingdom (late 6th to mid-3rd century BCE?) and the hypothesis of a hitherto unknown Late Hellenistic politybased at Ḥegrā (later 3rd to mid-1st century BCE?), but it also leads to reassess the extent of Achaemenid and Ptolemaicinvolvement in north-west Arabia.