▁describe ▁modern ▁programming ▁languages ▁have ▁significant ▁similar ities ▁to ▁P ā ṇ ini ' s ▁grammar ▁rules . ▁ ▁V ats y ay ana , ▁the ▁author ▁of ▁K ama ▁S ut ra . ▁ ▁It ▁is ▁believed ▁that ▁P atal i put ra ▁was ▁the ▁largest ▁city ▁in ▁the ▁world ▁between ▁ 3 0 0 ▁and ▁ 1 9 5 ▁B CE , ▁taking ▁that ▁position ▁from ▁Alexand ria , ▁Egypt ▁and ▁being ▁succeeded ▁by ▁the ▁Chinese ▁capital ▁Ch ang ' an ▁( mod ern ▁X i ' an ). ▁ ▁The ▁Gu pt as ▁ ▁Before ▁the ▁Gu pt as ▁ ▁When ▁the ▁last ▁of ▁the ▁Ma ury an ▁k ings ▁was ▁assass in ated ▁in ▁ 1 8 4   B CE ▁by ▁P ush y am it ra ▁Sh ung a , ▁India ▁once ▁again ▁became ▁a ▁collection ▁of ▁unf eder ated ▁kingdom s , ▁though ▁most ▁of ▁the ▁core ▁Mag ad ha ▁territ ories ▁remained ▁in ▁control ▁of ▁the ▁Sh ung a ▁Empire ▁who ▁engaged ▁in ▁conflicts ▁with ▁the ▁Ind o - G ree ks ▁to ▁secure ▁the ▁borders ▁of ▁India . ▁During ▁this ▁period , ▁the ▁most ▁powerful ▁kingdom s ▁were ▁not ▁in ▁the ▁north , ▁but ▁in ▁the ▁De cc an ▁to ▁the ▁south , ▁particularly ▁in ▁the ▁west . ▁The ▁north , ▁however , ▁remained ▁cult ur ally ▁the ▁most ▁active , ▁where ▁Buddh ism ▁was ▁spread ing ▁and ▁where ▁H indu ism ▁was ▁being ▁gradually ▁re made ▁by ▁the ▁Up an ish adic ▁movements