Unusually, for most of the battle, Wellington remained with the Reserve delegating command to his senior Lieutenant-Generals Rowland Hill and John Hope.

After his defeat at Nivelle, Marshal Soult fell back to a defensive line south of the town of Bayonne along the Adour and Nive rivers.

The rivers and the Bay of Biscay near Bayonne form a rough Greek letter Pi (π).

To gain room to manoeuvre, the British general had to establish his army on the east bank of the Nive.

[2] Soult launched a counter-attack with eight divisions against Hope the following day, and despite several fierce actions the British line held until reinforced by more troops coming up from Saint-Jean-de-Luz.

The left, under John Wilson, was held by Bradford and Campbell's independent Portuguese brigades north of Barroilhet.

The Light Division's outpost line alertly detected the coming attack, though 50 men were cut off and captured.

The picket line on Hope's left flank was quickly gobbled up by Reille's attack and 200 men captured.

This isolated Hill's 14,000 men and 10 guns on the east bank of the river, just as the French were reorganizing for an assault.

Seizing his opportunity, Soult rapidly switched six divisions and 22 guns to the east bank of the Nive and attacked Hill.

Defending a line between Petit Mouguerre (Elizaberry) and the Nive, the Allied corps held on for hours in a bitter fight.

The French near-mutiny forced Soult to reluctantly retreat into Bayonne, having lost 3,000 men against Anglo-Portuguese losses of 1,750.

Eventually, between 23 and 27 February, Wellington cut off Bayonne by crossing the mouth of the Adour west of the city.

[b] Leaving Hope to seal up the 17,000-strong French garrison, Wellington relentlessly pursued Soult and the rest of his army.

Accordingly, he took pains to send most of his Spanish units back to their home country, rightly concerned that they would inflict the same atrocities on French civilians that their own had suffered from Napoleon's armies.

As it happened, the French troops, hardened by years of plundering foreign civilians, began to despoil their own citizens.