The recent decades witnessed the appearance of new sources on the relation of the Byzantine Empire and the Hungarians. In many cases these sources modified our knowledge of the age. Previously, several researchers assumed that a Hungarian army attacked and took over two southern Italian Byzantine cities, Oria and Tarentum in 927. This view was based on the work of Romualdo Salernitano. However, his statement is wrong. The two cities were captured by Muslim troops, and the Italian author mistakenly wrote Hungarians instead of Muslims.
A Muslim author, Abu Firas tells us, that when the Byzantine Empire attacked the Hamdanid Principality in 958, a Hungarian military troop fought as part of the Byzantine army. Recently I became aware that Emperor Constantine VII also highlighted the presence of foreign troops in the Byzantine army in his oratio to his troops during the campaign. This confirms the facts we find in the work of the Muslim author.
A South Italian diploma mentions a peasant, called Leo filius Petri Ungri in 980. He or his descendant probably was a Hungarian warrior in Byzantine service.