Bulgarians are slavic, but their name isnt. Bulgar trbies were Turkish people.

The etymology of the name Bulgar is not fully understood; there are claims that it derived from the Turkic verb bulğa ("to mix", "shake, "stir") and its derivative bulgak ("revolt", "disorder") by some authorities.[14][15] A minority hypothesis derives it from bel gur ("five clans").[16]

According to our first tale, the Bulgars (or Proto-Bulgarians) were thunder-worshipping Turkic nomads, short, dark and bow-legged, who spent their lives on horseback wandering the steppes of Central Asia with their cattle, living in yurts, pillaging their neighbours and never settling down permanently. Despite their primitive craftsmanship and engineering skills, they were described as “more numerous than the grains of sand on the beach” and as fierce warriors, defeating at various times the professional armies of several kingdoms, including the Byzantine empire, with each Bulgar equipped with scale mail for himself and his horse, composite bow, sword, spear, shield, etc.

In 632 AD, the Bulgar khan (ruler) Kubrat, who had been educated in Constantinople for a time, learned statecraft from the Byzantines, seceded from the Western Turkic Khaganate and established a state on the north shores of the Black Sea with capital Phanagoria. The Bulgars settled down for about 30 years in what historians have called (Old) Great Bulgaria.