An armed conflict between Bulgaria and the nomadic Hungarians forced the latter to depart from the Pontic steppes and began the conquest of the Carpathian Basin around 895. Their invasion gave rise to the earliest reference, recorded some centuries later in the Gesta Hungarorum, to a polity ruled by a Romanian duke named Gelou. The same source also makes mention of the presence of the Székelys in Crişana around 895. The first contemporaneous references to Romanians – who used to be known as Vlachs – in the regions now forming Romania were recorded in the 12th and 13th centuries. References to Vlachs inhabiting the lands to the south of the Lower Danube abound in the same period.