Glavaš was born in 1763 in the village of Glibovac, near Smederevska Palanka, at the time part of the Sanjak of Smederevo, Ottoman Empire.

During this time Karađorđe Petrović spent several months in Glavaš's house, either as an apprentice or as a hajduk in hiding during wintertime.

His company guarded the Morava Valley and fought the Ottomans in the mountains of Niš and Novi Pazar for two months before being captured.

He is the subject of a Serbian heroic play written by Đura Jakšić, which was widely shown throughout Serbia in the 19th century.

As a young widow, his mother remarried when he was about 12 or 13 (and that's when he became a tailor's apprentice) so he had several half-siblings, many years younger to whom he played a kind of fatherly role in his mature age, especially as he did not have his own family.