The 12th Battalion, (the 12th Laurentian Independent Legion or just the Independant Legion in PAL versions), commonly known as Brenner's Wolves, is a small group of Rubinelle soldiers, led by Captain Brenner and later by Will in Advance Wars: Days of Ruin.
After the meteors struck, Brenner's Wolves went out to find survivors and help them from Bandits such as The Beast. Among these survivors were Will and Isabella. After defeating The Beast and helping the survivors find a food source, 12th Battalion joined the New Rubinelle Army in the war against the Lazurians. After defeating General Forsythe, Greyfield executes Forsythe, which causes the 12th Battalion to split from the New Rubinelle Army and fight against them, with the help of the remaining Lazurian Military. After Brenner dies, Will takes over as leader. Caulder then makes his children use The Great Owl, a giant bomber, to destroy 12th Battalion, but they manage to escape. He then reveals Isabella is one of his clone children, turning public opinion against her, causing her to defect to his side. After Penny is defeated, he orders her to kill herself and everyone on The Great Owl, but Isabella convinces her not to and Penny joins forces with Brenner's Wolves. Cyrus also helps 12th Battalion by telling them where to get the antidote to the disease, but dies shortly afterwards.
European names are donated in brackets.
|Captain Brenner (O'Brian)||Former leader, deceased|
|Isabella (Catleia)||Defected briefly but came back|
|Davis||Separated prior to Days of Ruin, defected, presumed deceased|
|Gage (Trak)||When 12th Battalion and Lazurian Army integrates|
|Tasha (Zadia)||When 12th Battalion and Lazurian Army integrates|
- 12th Battalion has the most COs, unless one doesn't consider the COs that join as part of them, considers Isabella to be both Intelligent Defense Systems and Brenner's Wolves CO's, and does not count The Beast and Davis because they are NPC's, then both 12th Battalion and IDS have four. If one doesn't consider those, then 12th Battalion has the most COs, having 8 (counting Davis and the people who join), while IDS has five (counting Isabella), the Lazurians have three, and New Rubinelle Army has three (counting Davis).
- 12th Battalion was named that because Days of Ruin is the 12th game in the Wars Series.
- 12th Battalion is the Days of Ruin version of Orange Star.