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). The title name does not have convincing etymologies, but it is probably of Turkic origin.
According to the Hungarian chronicles, Transylvania was ruled by a line of princes called Gyula, and their country was occupied by King Stephen I of Hungary (1000/1001–1038).
The title "Gyula" is known from the Hunnic times. The Chinese Shi Ji recorded hierarchy in the Hunnic state, after the Juki Prince (Ch. Xiang Wang) followed Luli or Guli Wang (), a third grade in the state hierarchy. Other Chinese phonetizations are kokli, and the initial phonetics is not only "gu" but also "yu": Yuli. The title was used by the states of the Hunnic circle in China, Europe, and Central Asia, among them the Hungarian Gyula, the Hephthalite Huns' Gula (in Byzantine sources also Golla), it is a component in the Indian Huna Mihirakula’s name, Constantine Porphyrogenitus noted it as Gila and Yula among the Kangar Pachinaks in his De Administrando Imperio (ca. 950), it is found in the Old Turkic Yula, and in the Khitan clan name Yila, in the Mongolian Jangar epos in the form Jula and in Mongolian expression "joloo" with a meaning "rein", earlier this title appeared when was established the Turkic empire Turkic Khaganate. During the Middle Ages it is known as a title and a personal name Ulug Bek, meaning "Great Prince".