The Conquest Brigade was founded at Tell Rifaat in late July 2012[2][13][26] as unification of three rebel groups that had previously operated in the countryside of northern Aleppo Governorate.

[14] The group was initially only active in the rural northern Aleppo Governorate,[2] and one of its first actions was the Battle of Anadan,[29][18] following which the Conquest Brigade was officially announced.

It cooperated with the al-Tawhid Brigade, and three Salafist / Salafi jihadist groups (al-Nusra Front, Ahrar al-Sham, and Harakat Fajr ash-Sham al-Islamiya) to establish al-Hay'a al-Sharia in Aleppo.

[33][19] In contrast to its good relations with various Islamist factions, the Conquest Brigade's relationship with the Syrian opposition's leadership, including the civilian SNC and the FSA's chief commanders, was more ambivalent.

[34] The group reportedly did not "listen to the orders of the regional leaders of the FSA", though was ready to meet with SNC senior member Samir Nashar in September 2012 to discuss a stronger cooperation with other rebel factions, such as the al-Nusra Front and the al-Tawhid Brigade.

[37] Though it had enjoyed cordial relations with ISIL during the early civil war,[13] the Conquest Brigade distanced itself from the jihadists after disagreeing with their harsh policies toward civilians in course of late 2013.

As result, elements of the Conquest Brigade were put under siege in Mare', with the SDF cutting them off from the west, while ISIL forces were located to the east.

[45] By August 2016, the Conquest Brigade had become part of the Turkish-backed Free Syrian Army (TFSA), and aided the Turkish Armed Forces during Operation Euphrates Shield against ISIL.

[49] The Conquest Brigade's stated aim has been to overthrow the al-Assad family's rule over Syria, and to establish a "Free Syrian government".

While besieging Menagh Military Airbase in August 2013, the group's members voiced their support for ISIL's plan to exterminate all Alawites (a religious minority) in a propaganda video.

[33] The Conquest Brigade had partially adopted the ideology of the Islamic State of Iraq and the Levant by this point, though distanced itself from Salafi jihadism after its violent split with ISIL.

[53] Of these, the following are known: Though eclipsed in its prominence and military prowess by several other rebel groups,[2] the Conquest Brigade was a relatively powerful and influential fighting force during the early civil war.

[4][20] At least one of its sub-groups, the Muthanna ibn Haritha Battalion, possessed tanks, technicals, and PK machine guns in 2012,[2] while the militia as whole had anti-tank warfare capabilities and produced its own homemade rockets and improvised explosive devices.

Syrian businessman Firas Tlass organized a meeting of the group's representatives with CIA agents in Gaziantep in August 2012, with the latter promising the former telecommunications equipment, and possibly weapons in case that the Conquest Brigade proved itself to be reliable.