The final deployment of British combat troops to Afghanistan will take place in June this year, the defence secretary has announced.
In a written ministerial statement, Philip Hammond said it will be the final phase of Operation Herrick - the UK's operation in Afghanistan - with the drawdown of combat troops due to be complete by the end of the year.
The announcement comes as Task Force Helmand, the UK's military headquarters in Afghanistan, was disbanded this week in the latest major step in the drawdown of British troops.
The British-led coalition task force's functions will now be absorbed into the wider US-led Regional Command (South West).
Announcing the final deployment of British troops to Afghanistan, Mr Hammond said around half of the units will come under the command of Brigadier Robert Thomas, who becomes the senior British officer in the province, serving as deputy commander Regional Command (South West).
The remainder will deploy elsewhere within Camp Bastion and in Kandahar and Kabul as part of the UK's overall contribution.
The number of British personnel in Helmand has reduced from a peak of more than 10,000 to just under half that number as Afghan National Security Forces have taken the lead in security across Afghanistan.
Units deploying will include The Queen's Royal Hussars (The Queen's Own and Royal Irish); Royal Artillery regiments; Royal Engineers; Signal Regiments; The Royal Logistic Corps; Royal Electrical and Mechanical Engineers; Royal Military Police as well as Royal Air Force squadrons.
Some 762 individuals from each of the services will also deploy, made up of 67 Royal Navy personnel, 320 Army personnel and 375 Royal Air Force personnel, while reservists will also be called up.
Mr Hammond said this deployment, which will be the 20th Operation Herrick, will be the final phase of the mission as UK Armed Forces end combat operations by December 31.
The closure of Task Force Helmand, which at its height had 137 bases across central Helmand, marks the end of the U K-led combat mission in Afghanistan, but British forces are continuing to support their Afghan counterparts with training and advice until the end of combat operations later this year.
Its disbandment is the latest in a series of steps marking the UK's withdrawal from Afghanistan - l ast month the MoD announced the closure or handover of three frontline bases in Helmand, leaving just one outside Camp Bastion.
Some 448 British forces personnel or MoD civilians have died in Afghanistan since the start of operations in October 2001.
The latest was Sapper Adam Moralee from 32 Engineer Regiment, who died on March 5 in Camp Bastion when he was injured while preparing equipment to be brought back to the UK.
Announcing the closure of Task Force Helmand, Mr Hammond said: "At this important point in the final year of the UK's lengthy and crucially important combat mission, it is only right to reflect on the significant achievements - and sacrifices - of the past eight years.
"The servicemen and women who have fought under the command of Task Force Helmand have protected the security of the UK and its people; prevented international terrorists from using Afghanistan as a base; and created the conditions for a brighter, more secure and more stable future for the country.
"However, the job is not over yet and UK troops will continue to operate in often risky and challenging conditions in Helmand supporting the Afghan forces and continuing the redeployment effort, until UK combat operations are concluded later this year."
At a ceremony to mark the end of Task Force Helmand, its final commander Brigadier James Woodham, said it was a "significant moment" in the drawdown.
"We are leaving Helmand in a better place and the Afghan National Security Forces are well set to continue to deliver security to the region."
Brig Robert Thomson, ceputy commander Regional Command (South West), added: "Having served in the province back in 2009, I have witnessed the progress delivered here by British forces under Task Force Helmand.
"In Regional Command (South West) we will continue that great work, supporting the Afghan National Security Forces and the people of Helmand, until the end of 2014 to see out the mission here alongside our US comrades."