The United Kingdom began a military intervention in Sierra Leone on 7 May 2000 under the codename Operation Palliser. Although small numbers of British personnel had been deployed previously, Palliser was the first large-scale intervention by British forces in the Sierra Leone Civil War. In early May 2000, the Revolutionary United Front (RUF)—one of the main parties to the civil war—advanced on the country's capital, Freetown, prompting the British government to dispatch an "operational reconnaissance and liaison team" (ORLT) to prepare to evacuate foreign citizens. On 6 May, the RUF blocked the road connecting Freetown to the country's main airport, Lungi. The next day, British soldiers began to secure the airport and other areas essential to an evacuation. The majority of those who wished to leave were evacuated within the first two days of the operation, but many chose to stay following the arrival of British forces.
After the effective completion of the evacuation, the mandate of the British forces began to expand. They assisted with the evacuation of besieged peacekeepers—including several British ceasefire observers—and began to assist the United Nations Mission in Sierra Leone (UNAMSIL) and the Sierra Leone Army (SLA). Despite the mission expansion, it was not until 17 May that British soldiers came into direct contact with the RUF. The rebels attacked a British position near Lungi airport, but were forced to retreat after a series of firefights. On the same day, the RUF's leader, Foday Sankoh, was captured by Sierra Leonean forces, leaving the RUF in disarray. After deciding that the RUF would not disarm voluntarily, the British began training the SLA for a confrontation. During the training mission, a patrol returning from a visit to Jordanian peacekeepers was taken captive by a militia group known as the West Side Boys. Negotiations achieved the release of five of the eleven soldiers, and three weeks into the crisis, British special forces launched a mission codenamed Operation Barras, freeing the remaining six. The success of Operation Barras restored confidence in the British mission; one academic suggested that its failure would have forced the British government to withdraw all its forces from Sierra Leone.