Changes in the political map over the control of the Malacca Strait, then the internal disputes of Siak and competition with Britain and the Netherlands, weakened the influence of the Siak Sultanate's hegemony over the territories it had once conquered. A tug of war between the interests of foreign forces can be seen in the Anglo-Dutch Treaties of 1870–71 between the British and the Dutch, made Siak in a dilemmatic position, and also in a weak bargaining position. Then based on the agreement on 26 July 1873, the Dutch East Indies government forced the Sultan of Siak to hand over the Bengkalis area to the Riouw Residency. But in the midst of this pressure, the Siak Sultanate still remained until Indonesia's independence, even though during the Japanese occupation most of the military power of the Siak Sultanate was no longer significant.