The Royal Marine Commandos are 356-years-old.

The Commandos are Britain’s amphibious light infantry force. They are organized in the 3 Commando Brigade, which is composed of 40 and 45 Commandos with about 700 Marines each — 42 Commando was also part of the Brigade but recently underwent a reorganization and it’s now focused on maritime counter-terrorism and interdiction.

The Royal Marine Commandos inhabit a grey area between Special Operations and conventional military forces.  Although not a SOF unit per se, their expertise in arctic, mountain, and expeditionary warfare on top of their tough selection and training process separates them from regular units of the British military. They are often called upon to support Britain’s SOF units.

Individual Royal Marines, however, do have the option to serve in the Special Forces Support Group (UKSG), a unit created to support SAS and SBS operations, much like the 75th Ranger Regiment has been doing for Delta Force and SEAL Team Six.