ith ic ▁period , ▁human ▁settlement s ▁existed ▁in ▁the ▁area ▁of ▁Lake ▁D ian , ▁close ▁to ▁modern ▁day ▁Kun ming , ▁Y unn an ' s ▁capital . ▁ ▁The ▁inhabitants ▁used ▁stone ▁tools ▁and ▁constructed ▁simple ▁wooden ▁structures . ▁ ▁The ▁Kingdom ▁of ▁D ian ▁ ▁The ▁D ian ▁culture ▁was ▁distributed ▁around ▁the ▁Lake ▁D ian ▁area ▁and ▁dated , ▁though ▁controvers ial , ▁between ▁the ▁ 6 th ▁century ▁BC ▁and ▁the ▁ 1 st ▁century ▁AD . ▁ ▁The ▁culture ▁is ▁divided ▁into ▁an ▁early ▁and ▁a ▁late ▁phase . ▁Under ▁Emperor ▁Wu , ▁a ▁series ▁of ▁military ▁campaign s ▁were ▁dispatch ed ▁against ▁the ▁D ian ▁during ▁the ▁south ward ▁expansion ▁of ▁the ▁Han ▁dynast y . ▁In ▁ 1 0 9 ▁BC , ▁the ▁kingdom ▁officially ▁became ▁a ▁v ass al ▁state ▁of ▁the ▁Han ▁emp ire . ▁ ▁Han ▁dynast y ▁▁ ▁In ▁ 1 0 9 ▁BC , ▁Emperor ▁Wu ▁sent ▁General ▁Gu o ▁Ch ang ▁() ▁south ▁to ▁Y unn an , ▁establish ing ▁the ▁Y iz hou ▁command ery . ▁The ▁command ery ▁seat ▁was ▁at ▁D ian chi ▁county ▁( present ▁day ▁Jin ning ). ▁To ▁expand ▁the ▁bur geon ing ▁trade ▁with ▁Bur ma ▁and ▁India , ▁Emperor ▁Wu ▁also ▁sent ▁Tang ▁M eng ▁() ▁to ▁maintain ▁and ▁expand ▁the ▁Five ▁Foot ▁Way , ▁ren aming ▁it ▁" S outh west ▁Bar bar ian ▁Circ uit " ▁( ). ▁By ▁this ▁time , ▁agricult ural ▁technology ▁in ▁Y unn