What two nations divided persia into northern and southern spheres of influence in 1907

Great Britain and Russia. Great Britain took the southern half, as it was geographically close to British holdings in Asia. Russia took the northern half, geographically close to Russia itself. There was also a smaller middle section in between that served as a buffer state. This action was a clause under the Anglo-Russian Entente, joining with France to create the Triple Entente, a powerful alliance that impacted WWI.