The Hungarian conquest of the Carpathian Basin, was a series of historical events ending with the settlement of the Hungarians in Central Europe at the turn of the 9th and 10th centuries. Before the arrival of the Hungarians, three early medieval powers, the First Bulgarian Empire, East Francia and Moravia, had fought each other for control of the Carpathian Basin. They occasionally hired Hungarian horsemen as soldiers. Therefore, the Hungarians who dwelt on the Pontic steppes east of the Carpathians were familiar with their future homeland when their conquest started.

The Hungarian conquest started in the context of a "late or 'small' migration of peoples". Contemporary sources attest that the Hungarians crossed the Carpathian Mountains following a joint attack in 894 or 895 by the Pechenegs and Bulgarians against them. They first took control over the lowlands east of the river Danube and attacked and occupied Pannonia (the region to the west of the river) in 900. They exploited internal conflicts in Moravia and annihilated this state sometime between 902 and 906.

Three main theories attempt to explain the reasons for the "Hungarian land-taking". One argues that it was an intended military operation, prearranged following previous raids, with the express purpose of occupying a new homeland. This view (represented, for instance, by Bakay and Padányi) mainly follows the narration of Anonymous and later Hungarian chronicles. The opposite view maintains that a joint attack by the Pechenegs and the Bulgarians forced the Hungarians' hand. Kristó, Tóth and the theory's other followers refer to the unanimous testimony provided by the Annals of Fulda, Regino of Prüm and Porphyrogenitus on the connection between the Hungarians' conflict with the Bulgar-Pecheneg coalition and their withdrawal from the Pontic steppes. An intermediate theory proposes that the Hungarians had for decades been considering a westward move when the Bulgarian-Pecheneg attack accelerated their decision to leave the Pontic steppes. For instance Róna-Tas argues, " fact that, despite a series of unfortunate events, the Magyars managed to keep their heads above water goes to show that they were indeed ready to move on" when the Pechenegs attacked them.