In April 2009, the 4th Infantry Division was relieved by the 1st Cavalry Division. The 155th Heavy Brigade Combat Team (HBCT), Mississippi National Guard, assumed the dual role of Garrison Command and Base Defense Operations Center in July 2009, relieving both the 949 BSB and the 1–108th FA. As of March 6, 2010 the 278th Armored Cavalry Regiment (Tennessee Army National Guard) officially took charge of Camp Taji Garrison Command, relieving the 155th. The garrison commander was COL Jeffrey H. Holmes. The 278th also assumed a dual role of Garrison Command and Base Defense Operations Center (BDOC). During the tenure of the 278th, many changes took place as the 278th had the initial role of downsizing Camp Taji. On May 1, 2010, The 278th Garrison Command took over the role of Law and Order and Military Police functions left vacant by the 26th Military Police Detachment. On July 20, 2010, the 256th Infantry Brigade Combat Team (Louisiana National Guard), the "Tiger Brigade," officially took charge of the Camp Taji Garrison Command and BDOC with LTC Eric Rivers as the garrison commander. The downsizing continued and the far north section of Camp Taji was turned over to the Iraqi Government in December 2010.