▁first ▁square . ▁▁ ▁A ▁piece ▁with ▁such ▁a ▁move ▁is ▁called ▁a ▁ ▁d abb ā bah ▁in ▁some ▁ch ess ▁variants . ▁The ▁move ▁was ▁described ▁by ▁the ▁Arab ic ▁ch ess ▁master ▁al - Ad li ▁c . ▁ 8 4 0 ▁in ▁his ▁( part ly ▁lost ) ▁ch ess ▁work . ▁( The ▁Arab ic ▁word ▁d abb ā ba ▁in ▁former ▁times ▁meant ▁a ▁covered ▁sie ge ▁engine ▁for ▁attack ing ▁w alled ▁fort ifications ; ▁today ▁it ▁means ▁" ar my ▁tank "). ▁ ▁This ▁is ▁rem in is cent ▁of ▁the ▁a for ement ioned ▁ch atur aj i , ▁where ▁the ▁ele ph ant ▁moves ▁as ▁a ▁ro ok . ▁ ▁The ▁German ▁historian ▁Johannes ▁Ko ht z ▁( 1 8 4 3 – 1 9 1 8 ) ▁suggests , ▁rather , ▁that ▁this ▁was ▁the ▁earliest ▁move ▁of ▁the ▁R ath a . ▁ ▁Ash va ▁( hor se ) ▁( also ▁sp elled ▁Ash wa ▁or ▁As va ): ▁moves ▁the ▁same ▁as ▁a ▁kn ight ▁in ▁ch ess . ▁ ▁Pad à ti ▁or ▁Bh ata ▁( foot - s old ier ▁or ▁inf antry ) ▁( also ▁sp elled ▁Ped ati ); ▁also ▁known ▁as ▁Sain ik ▁( war rior ): ▁moves ▁and ▁capt ures ▁the ▁same ▁as ▁a ▁pa wn ▁in ▁ch ess , ▁but ▁without ▁a ▁double - step ▁option ▁on ▁the ▁first ▁move . ▁ ▁Add itional ▁rules ▁Al - Ad li ▁mentions ▁two ▁further ▁differences