Delyo was born in Belovidovo (today Zlatograd) in the Smolyan region in the 17th century. He headed an armed detachment of rebels in the central Rhodopes and acted against the Ottoman authorities' Islamization of the local Bulgarian population. In 1720, he led a group of united rebel detachments that attacked Raykovo (today a neighbourhood of Smolyan) in revenge for the murder of 200 locals who refused to convert from Christianity to Islam. Delyo was mentioned in Historical notebook, an 18th-century document of disputed authenticity.
Delyo is a popular character in Rhodopean folk songs and legends. He is presented as a protector of the local population and an opponent of the local Ottoman authorities. He is glorified as being unkillable by a standard sword or gun, so his enemies cast a silver bullet in order to murder him. According to the legends, Delyo was the son of a poor craftsman and was taught tailoring by his uncle in Enidzhe (Giannitsa), but upon getting to know Bulgarians from around Gyumyurdzhina (Komotini), he organized a rebel detachment to counter the Ottoman atrocities.
The most popular folk piece about Delyo is "Izlel e Delyo haydutin" ("Delyo the hajduk has gone out"), a song from the Central Rhodopes that has been recorded in various versions. The song is best known as performed by Bulgarian folk singer Valya Balkanska. It was launched into space in 1977 as part of the Voyager 1 and Voyager 2 probes' Golden Record which includes a multicultural selection of music.
- Бакалов, Георги; Милен Куманов (2003). "Дельо войвода". Електронно издание "История на България" (in Bulgarian). София: Труд, Сирма. ISBN 954528613X.
- Енциклопедия България (in Bulgarian). том 2. София: Издателство на БАН. 1981.
- Стойкова, Стефана. "Дельо хайдутин". Българска народна поезия и проза в седем тома. (in Bulgarian). Т. ІII. Хайдушки и исторически песни. Варна: ЕИ "LiterNet". ISBN 978-954-304-232-6.
- "Делю Войвода" (in Bulgarian). Община Златоград. Retrieved 2009-02-16.
- Тодорова, Росица. Феноменът "Излел е Дельо хайдутин" в контекста на традиционната златоградска, родопска и общобългарска фолклорна мелодика (in Bulgarian). ИК "ЕТО". ISBN 954-9859-35-5.
- "Music On Voyager Record". NASA. Retrieved 2009-02-16.