2d Battalion 5th Marines was formed on July 1, 1914, and immediately sailed to the Caribbean to quell political turmoil in the Dominican Republic and Haiti.

In June 1917, as part of the United States' entry into World War I, the battalion sailed for France with the rest of the 5th Marine Regiment and the American Expeditionary Force.

[1] They fought during the Battle of Belleau Wood, Soissons, and the Meuse-Argonne campaign and were twice awarded the French Croix de Guerre with Palm.

In 1941, the battalion joined the newly formed 1st Marine Division at New River, North Carolina, but later relocated to the west coast of the United States.

Immediately following the 1950 North Korean invasion of South Korea, 2d Battalion, 5th Marines sailed from Camp Pendleton, California, to defend the Pusan Perimeter as a part of the famous "Fire Brigade".

The battalion also participated in the landing at Inchon, the liberation of Seoul, the Chosin Reservoir Campaign, and the defense of the East, Central, and Western Fronts before the war was over.

During this time, 2d Battalion, 5th Marines participated in combat operations at Huế, Quế Sơn, Phu Bai, Đông Hà and Phú Lộc.

Immediately after their return to Camp Pendleton in 1971, the battalion joined Operation New Arrivals, the relocation of Southeast Asian refugees to the United States.

During the return transit to the United States, the battalion was diverted to Bangladesh where it provided humanitarian relief as part of Operation Sea Angel.

On March 20, 2003, at approximately 2:30 am local time 2/5, as an element of the 15th Marine Expeditionary Unit, commenced operations in Iraq with the start of the Battle of Al Faw.

Relieved by the 1st bn of the Royal Netherlands Marine Corps (who were soon augmented by Japanese forces acting in a strictly non-combat role), 2/5 returned to Camp Pendelton in August.

BLT 2/5 made stops in Singapore, Bahrain, Qatar, United Arab Emirates, Kuwait, Jordan, and Australia.

The MEU had started its Certification Exercise (CERTEX) when it was redirected to the scene of several natural disasters in the Republic of the Philippines and Indonesia.

Following a brief port visit in Malaysia a devastating earthquake and subsequent tsunami struck northern Japan in vicinity of the city of Sendai.

The battalion was assigned to cover Now Zad and Musa Qala districts in northern Helmand province, and all cities and villages that lied in between.

Middendorf was awarded that year's, 2012, prestigious LtCol William G. Leftwich, Jr. Trophy for Outstanding Leadership for his actions while deployed with Golf Co., 2d Battalion, Fifth Marine Regiment, in the Helmand province of Afghanistan.