The Marines
The UNSC Marine Corps is a branch of the UNSCDF that is responsible for land-based military operations, as well as the protection of Naval vessels and installations from attack.
A rugged and diverse assortment of well equipped and well trained men and women, one of the Marine Corps's most notable conflicts was fighting a losing war against the Covenant's highly superior technology and numbers.
The UN Marine Corps (predecessor of the UNSC Marine Corps) were one of the primary combat groups fielded by the UN in the Interplanetary War, and were the first military organization deployed offworld in 2163. After the United Nations claimed victory in 2164, it reorganized into the UNSC, thereby changing the UN Marine Corps to the UNSC Marine Corps. Later, the UNSC Marine Corps would be responsible for dealing with Insurrectionist uprisings among UNSC colonies star systems.