The 2nd Division was one of the two divisions of the Portuguese Expeditionary Corps (CEP, Corpo Expedicionário Português), the main military force of Portugal that fought in the World War I Western Front on the side of the Allies.

The 2nd division assumed the responsibility of all the Portuguese sectors, rearranged as the Fauquissart, the Neuve Chapelle and the Ferme du Bois sectors (11 km of front), now under the operational control of the British XI Corps.

The 2nd Division was also planned to be moved to the rearguard on April 9, 1918, on the same day German Army launched operation Georgette, the great offensive whose main thrust was precisely on the sectors defended by the Portuguese Division.

In the resulting Battle of the Lys, the 20,000 Portuguese of 2nd Division suffered an assault from 100,000 Germans, supported by a heavy artillery bombardment.

Despite stubborn resistance, the Portuguese Division was overrun and lost c. 7,000 casualties.