The Defence Secretary Ben Wallace is to reveal details of a review of Britain’s armed forces and it includes dramatic changes to the British Army and the abolition of the Royal Marine Corps, who date back to 1664.
Last week Boris Johnson unveiled a strategic foreign and defence policy review which included plans to increase the number of nuclear warheads Britain deploys from 180 to 260.
On Monday, 22 March, Mr Wallace unveiled details of proposals, set out in a report called Defence in a Competitive Age, which aims to modernise Britain’s armed forces and enable them to defend the country’s interests "across multiple domains and in all corners of the globe."
Mr Wallace will unveil plans to shrink the size of the regular army from 80,000 to 70,000, the latest in a series of reductions.
Britain has never before had an army so small. Great Britain was created in 1707 when England and Scotland were united by the Act of Union and at that time the army was around 100,000 strong.
The last time it was below 70,000 was in 1652 when Oliver Cromwell - who founded the New Model Army during the English Civil War - subdued Ireland with an army of 68,000.
While the army loses out the Royal Navy will arguably benefit from Monday’s changes.
The navy has been promised more ships, sailors and submarines but the Royal Marines - a proud stand-alone regiment which was formed by King Charles II two years before the Great Fire of London - will be transformed into the Future Commando Force.
The navy will also be supplied with a brand new surveillance ship which will be given the task of protecting vital undersea cables.
The Daily Telegraph claimed the Multi Role Ocean Surveillance Ship, which could be operational by 2024, was specifically designed to protect cables from attack by Russian submarines.
Mr Wallace told the BBC on Sunday: "The lights could go out if we lose our critical national infrastructure across the board…Russia has certainly taken a deep interest in those cables, not only to the United Kingdom but obviously to the continent of Europe.”
The Ministry of Defence has had its budget increased by Boris Johnson’s government and Mr Wallace is expected to unveil increased investment in drones, artificial intelligence and cyber warfare.
There is however no talk yet of the British Army being kitted out with killer robots.
Mr Wallace is also announcing a new Ranger Regiment, which would "be able to operate discreetly in high-risk environments and be rapidly deployable across the world.”
It is not clear if the Ranger Regiment or the Future Commando Force will replace special forces like the Special Air Squadron (SAS) and Special Boat Squadron (SBS), which is currently used for high-risk and secret missions abroad.
In a statement Mr Wallace said: "In the coming years, we will broaden the spectrum of this worldwide engagement even further. Across a vast global footprint, we will be constantly operating to deter our adversaries and reassure our friends, integrating with our allies, and ready to fight should it be necessary."
The British government is also setting up a new Security Force Assistance Brigade which will provide training to “partner” nations such as the governments of Iraq, Afghanistan, Kenya and Belize.