Wikipedia
The Chalyzians or Khalyzians or Khalis or Khwalis ( Arabic: Khwarezmian, Byzantine Greek: Χαλίσιοι, Khalisioi, Magyar: Káliz) were a people mentioned by the 12th-century Byzantine historian John Kinnamos.
Kinnamos in his epitome twice mentions Khalisioi in the Hungarian army. He first describes them as practising Mosaic law; though whether they were actually Jews is unclear because other editions state that they were Muslims. They were said to have fought against the Byzantine Empire as allies of the tribes of Dalmatia in 1154, during Manuel Comnenus's campaign in the Balkans.
Prior to the years 889–92 some Khalis and Kabars (Kavars) of the Khazar realm had joined the Hungarian (Magyar) federation that had conquered and settled in Hungary. Another group had joined the Pechenegs. Al-Bakri (1014–1094) states that around 1068 A.D. there were considerable numbers of al-Khalis amongst the nomadic Muslim Pechenegs (Hungarian: Besenyő), that lived around the southern steppes of Russia.
He also mentions that the original al-Khalis living within the Khazar realm may have been foreign slaves from Byzantine Constantinople and/or other lands. The Pechenegs gave them the choice of staying in their country, where they could inter-marry or leave for another country of their choice. Anna Komnena in her Alexiad mentions a Pecheneg chief named Khalis.
Abraham Harkavy hypothesized that the Khalyzians were refugees fleeing the destruction of their khaganate by the Kievan Rus in the 960s CE and the Pecheneg influx which followed in the 970s. A contemporary of Harkavy's, the Polish historian August Bielkowski, suggested that the Khalyzians were identical with the tribe known in Russian sources as the Khvalisy; hence they may have been connected to the Arsiya.
The maternal ancestors of the Magyarized Pecheneg clan Aba, to which the Hungarian king Samuel Aba (1041–47) belonged, were according to Hungarian chronicles of Khwarazmian origin (de gente Corosmina, de Corosminis orta).