▁region ▁of ▁that ▁territory , ▁the ▁administrative ▁capital ▁of ▁which ▁was ▁Kab uch an ▁( K uch an ▁in ▁the ▁vul gate ). ▁ ▁A ▁short ▁while ▁later , ▁the ▁Par ni ▁seized ▁the ▁rest ▁of ▁Par th ia ▁from ▁And rag or as , ▁killing ▁him ▁in ▁the ▁process . ▁Although ▁an ▁initial ▁pun itive ▁expedition ▁by ▁the ▁Sele uc ids ▁under ▁Sele uc us ▁II ▁was ▁not ▁successful , ▁the ▁Sele uc ids ▁under ▁Ant io chus ▁III ▁re capt ured ▁Ar s ac id ▁controlled ▁territory ▁in ▁ 2 0 9 ▁B CE ▁from ▁Ar s aces ' ▁( or ▁Tir id ates ') ▁successor , ▁Ar s aces ▁II . ▁Ar s aces ▁II ▁su ed ▁for ▁peace ▁and ▁accepted ▁v ass al ▁status , ▁and ▁it ▁was ▁not ▁until ▁Ar s aces ▁II ' s ▁grand son ▁( or ▁grand - ne p hew ) ▁Ph ra ates ▁I , ▁that ▁the ▁Ar s ac ids / Par ni ▁would ▁again ▁begin ▁to ▁assert ▁their ▁independence . ▁ ▁For ▁the ▁histor i ograph ers ▁upon ▁whose ▁documentation ▁the ▁reconst ruction ▁of ▁early ▁Ar s ac id ▁history ▁depends , ▁the ▁Par ni ▁had ▁by ▁then ▁become ▁ind ist ingu ish able ▁from ▁the ▁Par th ians . ▁ ▁Leg acy ▁The ▁se iz ure ▁of ▁Ast ab ene ▁in ▁ 2 3 8 ▁B CE ▁nomin ally ▁marks ▁the ▁beginning ▁of ▁the ▁Ar s ac id ▁era , ▁which ▁is ▁named ▁after ▁Ar s aces , ▁and ▁the