Sultan Abdul Hamid II established the Ullah millet, a separate millet for the Aromanians within the Ottoman Empire.

Abdülhamid II or Abdul Hamid II was the 34th sultan of the Ottoman Empire, from 1876 to 1909, and the last sultan to exert effective control over the fracturing state. He oversaw a period of decline with rebellions, and presided over an unsuccessful war with the Russian Empire (1877–78), the loss of Egypt, Cyprus, Bulgaria, Serbia, Montenegro, Tunisia, and Thessaly from Ottoman control (1877–1882), followed by a successful war against Greece in 1897, though Ottoman gains were tempered by subsequent Western European intervention.

The Ullah millet was a separate millet within the Ottoman Empire. It was established by the Ottoman authorities for the Aromanians in 1905, during the rise of nationalism in the Ottoman Empire. Although the Megleno-Romanians are also sometimes called Vlachs, the Ullah millet was not intended for them.

In the Ottoman Empire, a millet was an independent court of law pertaining to "personal law" under which a confessional community was allowed to rule itself under its own laws.

The Aromanians are an ethnic group native to the southern Balkans who speak Aromanian, an Eastern Romance language. They traditionally live in central and southern Albania, south-western Bulgaria, northern and central Greece, and North Macedonia, and can currently be found in central and southern Albania, south-western Bulgaria, south-western and eastern North Macedonia, northern and central Greece, southern Serbia, and south-eastern Romania. An Aromanian diaspora living outside these places also exists. The Aromanians are known by several other names, such as "Vlachs" or "Macedo-Romanians".