(Chapter III of Narrative of The Burmese War by Major John Snodgrass, British Army, the Military Secretary to the Commander of the British expeditionary force and the Assistant Political Agent in Ava.)
That the court of Ava had been for many months preparing for a rupture with the government of India, the tone and conduct of the governors of Arracan and the provinces lying contiguous to our frontier, and the assemblage of troops in that quarter, afford the strongest evidence; offensive warfare was obviously intended.
But the invasion of their own frontiers, more especially of the distant coasts of Pegu and Tenasserim, seems to have been wholly overlooked in their warlike preparations.
State and Position of the Burmese Forces at the Period of Our Landing
During the preceding cold season, while the British troops occupied the southern parts of the Chittagong district, considerable bodies of Burmese had crossed the Arracan mountains; and although they at that time did not venture to show themselves in force upon our frontier, reports were industriously circulated by them, that, unless our claim upon the island of Shaporee (St. Martin or Shin-ma-phyu Island) was speedily relinquished, an army of thirty thousand men would invade Bengal.