After the fall of Pegu, remnants of Mon resistance fell back to the upper Tenasserim peninsula , and remained active there with Siamese support. However, the resistance was disorganized, and did not control any major towns. It remained active only because Konbaung's control of the upper Tenasserim peninsula in 1757-1759 was still largely nominal. Its effective control still did not extend beyond Martaban as the majority of the Konbaung armies were back north in Manipur and in the northern Shan states. However, no single southern leader emerged to rally the Mon populace as Alaungpaya did with the Burmans in 1752. A rebellion broke out in 1758 throughout Lower Burma but was put down by local Konbaung garrisons. The window of opportunity came to a close in the second half of 1759 when the Konbaung armies, having conquered Manipur and the northern Shan states, were back down south, preparing for their invasion of the Tenasserim coast and Siam. The Konbaung armies seized the upper Tenasserim coast following the Burmese-Siamese War , and pushed out the Mon resistance farther down the coast.  The resistance was driven out of Tenasserim in 1765 when Alaungpaya's son Hsinbyushin seized the lower coastline as part of the Burmese-Siamese War .
Question: When did the remnants of Mon resistance fall back to the upper Tenasserim peninsula?
Answer: After the fall of Pegu