they were frequently hired as mercenaries by the surrounding polities and had led their own campaigns in this area for decades. This area had been sparsely populated since Charlemagne's destruction of the Avar state in 803, and the Magyars were able to move in peacefully and virtually unopposed during the 9th century. The first mention of them living in the region dates back to 862. The conquest proper started from 894, when armed conflicts opened with the Bulgarians and Moravians after the requests for help from Arnulf, Frankish king and Leo VI, Byzantine emperor. During the occupation, the Hungarians found sparse population and met no well-established states or effective control of any empire in the plain. They were able to take over the basin quickly, defeating the First Bulgarian Tsardom, disintegrating the Principality of Moravia, and firmly establishing their state there by 900. The invasion wasn't aimed at plundering the acquired lands as attacks were led by gyula Árpád and kende Kurszán, the two highest-ranking leaders, who left no mass graves behind them showing that the transition back to an Avar-like system was peaceful for the locals. Archaeological findings indicate that they settled in the lands near the Sava and Nyitra by this time. Military achievements The principality as a warrior state, with a new-found military might, conducted vigorous raids ranging widely from Constantinople to central Spain. Three major Frankish imperial armies were defeated decisively by the Hungarians between 907 and 910. The Hungarians succeeded in extending the de jure Bavarian-Hungarian border to the River Enns (until 955), and the principality was not attacked from this direction for 100 years after the Battle of Pressburg. The intermittent Hungarian campaigns lasted until 970, but two military defeats in 955 (Lechfeld) and 970 (Arcadiopolis) marked a shift in the evolution of the Hungarian principality. Transition The change from a ranked chiefdom society to a state society was one of the most important developments during this time. Initially, the Magyars retained a semi-nomadic lifestyle, practising transhumance: they would migrate along a river between winter and summer pastures, finding water for their livestock. According to Györffy's theory derived from placenames, Árpád's winter quarters -clearly after his occupation of Pannonia in 900- were possibly in 'Árpádváros' (Árpád's town), now a district of Pécs, and his summer quarters -as confirmed by Anonymus- were on Csepel Island. Later, his new summer quarters were in Csallóköz according to