the six vilayets (ottoman turkish: ولايت سته, vilâyat-ı sitte) or the six armenian vilayets (armenian: վեց հայկական վիլայեթներ, vets' haykakan vilayet'ner), were the main armenian-populated vilayets of the ottoman empire (van, bitlis, diyarbekir, sivas, erzurum, mamuret-ul-aziz).