Activated on 26 May 2004, the Vanguard Brigade was the first new Brigade formed under the Army's modularity Transformation initiative and was "out front" setting the pace for the Army while simultaneously preparing to deploy to Iraq in support of the Global War on Terrorism.

After completing a six month train-up and a Mission Rehearsal Exercise at JRTC, the Brigade deployed to Iraq in January 2005 and assumed its mission as the MND-Baghdad main effort on 4 March 2005.

After assuming responsibility for an area that had previously been occupied by two brigades, the Vanguard Brigade ensured the success of numerous milestone events including the seating of the first freely elected Iraqi government and more than 100 subsequent sessions of the Iraqi Transitional National Assembly; the trial of Saddam Hussein; the vote on the Constitutional Referendum; the elections for the first 4-year Iraqi Government; the activation and training of the 5th Iraqi Army Brigade, 6th Division; and security of the Iraqi strategic center of gravity within the International Zone.

The Vanguard Brigade established partnerships and conducted joint combat operations with 21 Iraqi Security Force Battalions and established a Joint Operations and Intelligence center.

The Vanguard Brigade remained steadfast in its year-long mission to conduct full-spectrum counter insurgency operations in order to defeat Anti Iraq Forces, secure key terrain, support government and economic development, and develop Iraqi Security Force capability to create a security environment that facilitates the completion of the United Nations Security Council Resolution 1546.

The Brigade returned to Fort Stewart in January 2006 to conduct reintegration, reset and regeneration operations in preparation for its next deployment.

Following regeneration, the Brigade began its preparation for Operation Iraqi Freedom (OIF) V with a home station readiness exercise called Vanguard Focus in March 2007. After months of training and preparation, the Brigade completed its Mission Rehearsal Exercise at the National Training Center (NTC) in May 2007. Certified for combat, the Vanguard Brigade was ready for its next deployment.

In October 2007, the brigade deployed for its second tour of duty in support of the Global War on Terrorism and arrived in Iraq during the closing stages of surge operations. The Brigade assumed its mission as the Multi-National Division - Center (MND-C) main effort in Iraq's Babil province while providing tactical overwatch of the Najaf and Karbala provinces.

During OIF 07-09, the brigade's completed countless operations, shaped numerous landmark events, and founded many initiatives which all contributed to greater security, improved infrastructure, and the advancement of the Iraqi military and police forces. The mission was such an overwhelming success that the Brigade was able to hand over its area of operations to Provincial Iraqi Control (PIC) prior to the end of its deployment and seamlessly transfer its authority to a new brigade ready to continue the positive momentum.

The Brigade returned to Fort Stewart in December 2008 to conduct reintegration, reset and regeneration operations. In March 2009, the brigade began its own transformation from heavy armor to light infantry and began preparation for its next road to war.