At the start of the Peninsular War, Brenier was assigned to Jean Andoche Junot's army for the 1807 Invasion of Portugal. During the Battle of Vimeiro on 20 August 1808, Brenier's brigade surprised and drove back two British battalions, but it was soon defeated. Wounded and captured by the British, he returned to France from captivity in 1809. In 1810 he again went to Portugal, serving under MarshalAndré Masséna. After the first Siege of Almeida, Brenier became its governor and held the post during Massena's unsuccessful third French invasion of Portugal in 1810-1811. After the French army's retreat from Portugal, Arthur Wellesley, 1st Duke of Wellington's British army blockaded Almeida. While marching to Brenier's relief, Massena failed to fight his way past Wellington in the Battle of Fuentes de Onoro. During the night of 10 May 1811 Brenier threaded his 1,400-man garrison through the lines of the 13,000-strong British investment force in the second Siege of Almeida. His engineers set explosives which demolished the fortifications after his men got away. During the pursuit he lost 360 men, but the pursuing British ran into an ambush set by some troops of Jean Reynier's II Corps and the rest of Brenier's soldiers safely reached French lines. Wellington wrote, "I have never been so much distressed by any military event as by the escape of even a man of them." This brilliant exploit earned Brenier promotion to general of division. During the Battle of Salamanca, Brenier's 4,300-man 6th Division arrived inopportunely at the unfolding disaster on the left flank. Wellington's forces had just crushed the divisions of Jean Guillaume Barthélemy Thomières and Antoine Louis Popon de Maucune when Brenier's men came up, winded from a rapid march. Still in battalion columns, the division was first swamped with fleeing troops from Maucune's division, then beset by a brigade of British heavy dragoons led by John Le Marchant. Attacked before they could form square, Brenier's battalions were overrun and routed. However, some troops managed to rally in a forest and emerged from the woods in battle order. The heavy dragoons attacked again, this time breaking the division for good, but Le Marchant was killed in the action.
Later career
Brenier played an honorable part in the campaign of 1813. Leading the 9th Division in Marshal Michel Ney's III Corps, he was severely wounded at the Battle of Lützen in Saxony on 2 May 1813. In 1814 he became commander of the 16thmilitary district and supervised the fortification of Lille. Afterwards he took over the command of the city of Brest, where his actions during the Hundred Days earned him a sword of honour voted him by the municipal council. Brenier became a Count, the Inspector General of the Infantry from 1816 to 1818, and the supreme commander in Corsica from 1820 to 1823. He retired in 1827 and died on 8 October 1832. His name appears on the west side of the Arc de Triomphe in Paris, on Column 35.
