Bandar Kasim, in spite of warnings, was again oppressing his people in the Sadong. The Rajah had deposed him in 1848, and had appointed his brother, Abang Leman,[176] in his place, but the change brought no benefit to the people, it gave them but an additional tyrant, for both were now behaving badly, and the Bandar had to be removed.
After visiting Labuan, the Rajah went to Penang for a much-needed change, and there received instructions from the Foreign Office to proceed to Siam on a diplomatic mission. He left for Bangkok in August. To quote his own words: "The mission was a dead failure, as the Siamese are as hostile and opposed to Europeans as any people can well be. I had a very trying time of it, and altogether got rid of an unpleasant and critical position without loss of national and individual credit." A short time before an American mission had also been similarly repulsed.
During the Rajah's absence, an envoy from the United States had arrived at Kuching bearing a letter from the President addressed to him as Sovereign Prince of Sarawak, and expressing a desire to enter into friendly relations. The envoy informed the Rajah by letter that having been entrusted with full powers he was ready to sign a treaty with Sarawak, and that he was to thank the Rajah "in the name of the American nation for his exertions in the suppression of piracy," and to compliment him on his noble and "humane endeavours to bring his subjects and the neighbouring tribes of Malays into a condition of civilisation." Lord Palmerston saw no objection to the Rajah entering into diplomatic relations as Rajah of Sarawak with the United States.[177]
In January, 1851, the Rajah, leaving Captain Brooke in charge, again left for England on account of the bad state of his health. He came home for rest and quiet, but this was denied him, and he had to sum up all his energies, and expend time and money to contend against the active and bitter hostility of his Radical opponents in England, who in spite of adverse majorities in the House of Commons and the opposition of some of the most prominent politicians in both Houses, continued their malignant persecution with great persistency both in and out of Parliament.