pay a fine of a one thousand pounds. The Burmese neither wanted nor were prepared for a war. They quickly accepted the British demands. The British officer on the scene, Commodore George Lambert, blockaded the port of Rangoon. On 18 February 1852, Dalhousie increased the demand to one hundred thousand pounds sterling. On 12 April 1852, war was declared and the Royal Navy invaded Rangoon. King Pagan sent four armies to meet the British. The Burmese put up tough resistance at Bassein (Pathein) and Pegu but by June, much of Lower Burma was captured by the British. After the end of the rainy season, in November, the British captured Prome, and pushed up to Myede on the Irrawaddy, and took Toungoo on the Sittaung, facing minimal Burmese resistance. In December, Prince of Mindon raised a rebellion against his brother the king. On 20 December 1852, the British issued a proclamation of annexation, taking Lower Burma, up to the latitude running directly east–west across the country to the borders of Karenni states, 6 miles (9.65 km) north of Myede (and Toungoo). It took three years to "pacify" the province. Burmese resistance leader Myat Tun, with 4,000 followers, waged guerrilla warfare, repulsing three British attacks before being defeated by a fourth one led by a British brigadier general. In 1857, an ethnic Karen leader began another round of guerrilla warfare in the Irrawaddy delta, which was only defeated after eight years of fighting. Siam (1849–1855) Although it failed to dislodge the Burmese from Kengtung and Sipsongpanna at the beginning of the century (1803–1808), Siam never gave up its claims on these lands. They tested the waters in 1849, by raiding as far north as Kengtung. But when the Second Anglo-Burmese War started, the Siamese viewed it as their opportunity to take over the trans-Salween states. In late 1852, a large infantry and elephant force marched from Chiang Mai and launched a two-pronged invasion of Kengtung. Burma could respond only after the new king Mindon had seized power in February 1853. Because he was still concerned about the British threat, Mindon could only send several thousand infantry troops from the Mone (Mong Nai) garrison to relieve the Siamese siege of Kengtung. With the troops by Kenghung sawbwa, the Burmese eventually drove out the Siamese but only after heavy loss of life. In 1854, the largest Siamese invasion force, consisted of Laotian levies, tried