Sarawak is broken away from Brunei on September 24, 1841, and becomes a protectorate of the United Kingdom; James Brooke is appointed rajah.

After serving in the First Anglo-Burmese War, in which he was severely wounded in battle, Brooke had returned to England in 1825 to recover from his injury.

Despite his attempts to return into service, he was unable to return to his station in India before his temporary leave from the service expired.

Overstaying his furlough had resulted in his position in the military being forfeited, but he had been awarded a pension by the government for his service.

He had continued on from India and gone to China to improve his health.

On his way to China in 1830, he had seen the islands of the Asiatic Archipelago, still generally unknown to Europeans.

Returning to England, he made an abortive trading journey to China in the Findlay before his father died in 1835.

Inspired by the adventure stories regarding the success of the East India Company (EIC), where his father had been serving especially in the efforts of Stamford Raffles to expand Company influence in the Asiatic Archipelago, he had purchased a schooner named Royalist using the thirty thousand pounds left to him by his father.

He recruited a crew for the schooner and trained in the Mediterranean Sea in late 1836 before beginning sailing for the Far East on October 27, 1838.

By July 1839, he had reached Singapore and come across some British sailors who had been shipwrecked and helped by Pengiran Raja Muda Hashim, the uncle of Sultan Omar Ali Saifuddin II of Brunei.

Brooke had originally planned to sail to Marudu Bay in northwestern Borneo, but the British Governor-General in Singapore had asked him to thank Raja Muda Hashim in southwestern Borneo.

The following month he had sailed to the western coast of the island and on August 14, 1839, berthed his schooner on the banks of the Sarawak River and met Hashim to deliver the message.

The Raja had told Brooke that his presence in the area was to control a rebellion against the Sultanate of Brunei caused by the oppressive policies of Pengiran Indera Mahkota, a kinsman of the Sultan.

Mahkota had earlier been dispatched by the Sultan to monopolize the antimony in the area; which as a result had directly affected the incomes of the local Malays there and growing frustration from the indigenous Land Dayak, who had been forced to work in the mines for about ten years.

It has also been alleged that the rebellion against Brunei was aided by the neighboring Sultanate of Sambas and the government of the Dutch East Indies, who wanted to establish economic rights over the antimony.

Despite Hashim's efforts to stop the rebellion, it came to no avail, thus leading him to seek direct help from Brooke.

Responding to the request, a force of local natives raised and led by Brooke had managed to temporarily stop the rebellion.

Brooke had been granted a large quantity of antimony from the local mines and authority in the Sarawak River area as a reward.

After that, Brooke became embroiled in Hashim's campaign to restore order in the area.

Brooke had returned to Singapore and spent another six months cruising along the coasts of the Celebes Islands before returning to Sarawak on August 29, 1840.
 
Upon his returning to Sarawak, the rebellion against Brunei's rule was still in progress.

He had managed to completely suppress the rebellion and pardoned the rebels for joining his side, providing positions in some administrative authority while limiting their power.

Despite the initial refusal of Hashim to pardon the rebels and wanting to execute them all, Brooke had persuaded Hashim to forgive them, as he had taken the major part in their suppression.

In exchange for Brooke's continuous support towards the Sultanate and rental payment of £500, he had been awarded the Kuching area from the Sultanate of Brunei; this will later become Sarawak First Division.

Hashim, however, had begun to think twice about giving the territory to Brooke, a doubt fanned by Mahkota, who had been deprived of his power in the area in favor of Brooke.

This led Hashim to constantly delay the recognition of concession, angering Brooke, who, with Royalist fully armed, had gone ashore to Hashim's audience chamber and called on him to negotiate.

With little choice, and putting the blame mainly on Mahkota, Hashim grants Sarawak to Brooke on September 24, 1841.