▁the ▁ 1 5 th - 1 8 th ▁centuries . ▁In ▁early ▁times , ▁the ▁D ör bet ▁and ▁the ▁D zung ars ▁were ▁ruled ▁by ▁coll ater al ▁branches ▁of ▁the ▁Chor os . ▁The ▁D ör b ets ▁are ▁distributed ▁among ▁the ▁western ▁provinces ▁of ▁Mong olia , ▁Kal my k ia , ▁and ▁in ▁a ▁small ▁portion ▁in ▁Heil ong ji ang , ▁China . ▁In ▁modern - day ▁Mong olia , ▁the ▁D ör b ets ▁are ▁centered ▁in ▁U vs ▁Province . ▁ ▁History ▁A ▁D ör ben ▁cl an ▁of ▁Du wa ▁So hor ' s ▁four ▁sons ▁existed ▁within ▁the ▁K ham ag ▁Mong ol ▁conf eder ation ▁in ▁the ▁ 1 2 th ▁century ; ▁but ▁their ▁relation ▁with ▁the ▁D ör b ets ▁is ▁unclear . ▁However , ▁the ▁D ör b ets ▁appeared ▁in ▁the ▁early ▁ 1 5 th ▁century ▁as ▁part ▁of ▁the ▁Four ▁O ir ats . ▁The ▁name ▁probably ▁means ▁ ▁" d ör öv "; ▁" four " ▁( Middle ▁Mong ol ian : ▁d ör be ). ▁ ▁In ▁the ▁ 1 7 th ▁century , ▁the ▁leader ▁of ▁D ör b ets ▁was ▁Dal ai ▁Ta ishi ▁( d . 1 6 3 7 ). ▁In ▁order ▁to ▁un ite ▁the ▁O ir ats , ▁Dal ai ▁Ta ishi ▁used ▁the ▁method ▁of ▁marriage ▁of ▁convenience ; ▁Dal ai ▁Ta ishi ▁and ▁Kh osh ut ▁leader ▁Gü sh i ▁Khan ▁married ▁the ▁T org h