The origin of a highly developed civilization which existed in the south-western part of the Arabian peninsula from the early 1st millennium ВС till the late 6th century AD still remains obscure. New epigraphic material discovered by the Soviet-Yemenite multidisciplinary expedition in 1983-1991 at the site of Raybun (Inland Hadramawt) proved to be of considerable value for elucidating some details of this process. It is commonly recognized that the impact of the Sabae-ic language and the Sabaean culture played the decisive part in the formation of local varieties of South Arabian civilization, including the Hadramitic one. The analysis of onomastic and linguistic data with due regard for palaeographic criteria demonstrates that there were at least two periods during which the culture of ancient Hadramawt fell under a strong influence of Saba': at the very beginning of the 1st millennium ВС and in the course of military campaigns of the Sabaean mukarrib and malik (king) Karib'il Watar (early 7th century ВС).