thumb|284x284px|King [[Stephen I of Hungary|St. Stephen captures Gyula (Chronicon Pictum)]]
Gyula (Yula, Gula, Gila) was, according to Muslim and Byzantine sources, the title of one of the leaders, the second in rank, of the Hungarian tribal federation in the 9th–10th centuries. In the earliest Hungarian sources, the title name is only recorded as a personal name (Gyyla, Geula, Gyla, Iula). It is often traditionally considered of Turkic origin, however other etymological explanations have recently been proposed, as both Hungarian as well as Turkish share ancestral - linguistic similarities. According to Lóránd Benkő, the word originates from Old Turkic, where it can be found as a personal- (altaic: Kaltanjula), genus- (Bulgar: Дуло - Dulo) and tribal (Pecheneg: Yula, Bashkir: Yulaman) name. It was transferred as a title in the Hungarian language, presumably from the Khazar language. Benkő assumed a *ǰula form derived from a Turkic word meaning 'torch'. Related words of Turkic origin can be found in the Hungarian language: gyúl (to catch fire, to be ignited) cf. West Old Turkic: *jul; East Old Turkic: *yul. András Róna-Tas and Árpád Berta also consider the latter to be Turkic. On the other hand, Dániel Németh suggested that the word may have Uralic origins, due to Hungarian influences reaching even the far Easts. He derives it from the Finno-Ugric *ćȣlkɜ-, *ćȣ̈lkɜ- (shines, gleam, glitter) and the Ugric*čittɜ- (shine, illuminate) words. This theory was criticized by János B. Szabó and Balázs Sudár: "Recently, Dániel Németh presented a strongly hypothetical etymological proposal based on both a Turkic and Finno-Ugric linguistic background, deviating from historical data." The major one, called kende (or künde), enjoyed nominal leadership, while effective power was exercised by his colleague, inferior in rank, called the gyula.
The Byzantine Ioannes Skylitzes in the second half of the 11th century recounted (using earlier written sources) the baptism of the Hungarian chieftain Gyula (or gyula) in Constantinople in the mid-10th century. According to Ioannes Skylitzes, Gyula stayed true to his new faith and took a missionary bishop, Hierotheos, with him. According to the author of the Gesta, Zombor (Zubor) was the father of the younger Gyula (Geula/Gyla).
The Chronicon Pictum
thumb|200px|The first page of the Chronicon Pictum
The chronicle increased the members of the Gyula family with the same name to three.
The family tree of the Gyula family according to the Chronicon Pictum: who was later considered to be the ancestor of the dynasty that ruled Hungary until 1301.