The Portuguese Expeditionary Corps (CEP, Portuguese: Corpo Expedicionário Português) was the main military force from Portugal that fought in the Western Front, during World War I. Portuguese neutrality ended in 1916 after the seizure of German merchant ships resulted in Germany declaring war. The expeditionary force was raised soon after and included around 55,000 soldiers.

At the outbreak of the First World War, Portugal had declared its neutrality. The country remained neutral until 1916, though occasional skirmishes between Portuguese and German colonial troops occurred in Africa. In March 1916, the Portuguese government seized a number of merchant ships belonging to the Central Powers which were anchored in Lisbon; the German government took this as a hostile act and declared war.^[1]

The government announced it would raise an expeditionary force to fight on the Western Front, with the first units being raised by July. In early 1917, the force was split into two elements:^[2]

• Portuguese Expeditionary Corps (Corpo Expedicionário Português, or CEP)
• Independent Heavy Artillery Corps (Corpo de Artilharia Pesada Independente, or CAPI)

The CEP was an infantry force of two divisions (a single army corps) with a nominal strength of about 55,000 men. The CAPI, meanwhile, was an artillery force of nine batteries of heavy artillery, manned by Portuguese gunners with artillery provided by France and the United Kingdom. The CEP would fight under British control as part of First Army, whilst the CAPI would fight under French control.^[3]

The CEP was shipped to France in early 1917, where the first groups received training in trench warfare and were equipped with British small arms.^[4] The first units began to deploy in May, and a sector of the frontline was fully held by the CEP by November; by the end of October, just under 60,000 troops had been sent to France.^[5]

From the 6 November 1917, CEP took charge of the whole "Portuguese Sector" of the Western Front, with a total 18 km frontage. In accordance with the Ally practice, the Sector included three lines of defense. The 1st Line of Defense included the Front Line (A-Line), the Support Line (B-Line) and the Reserve Line (C-Line). The 2nd Line included the Village Line (brigade headquarters line) and the Corps Line. Finally, the Army Line formed the 3rd Line of Defense.^[6]

The Portuguese Sector was divided in four brigade sectors. Each brigade had two battalions in the front (each defending a sub-sector of the brigade sector), one battalion in support and another in reserve. Each of the CEP's two divisions controlled two brigade sectors, having a third brigade in reserve.^[7]

CEP suffered the first German attack on the 4 June 1917, made against Neuve Chappelle sector. The attack was repelled by the 35th Portuguese Infantry Battalion, which had deployed to the front trenches just two days before. On the night of 12 June, a more intense German attack is carried away against Ferme du Bois and Neuve Chappelle sectors, being repelled by the 2nd, 3rd and 7th infantry battalions.^[8]

On the 14 August, the Germans launch a strong attack against the Portuguese lines. After an intense artillery bombardment, a Stosstruppen battalion assaulted the Neuve Chappelle and Fauquissart sectors. In the defense against this attack, 2nd Lieutenant Hernâni Cidade of the 35th Infantry Battalion stood out, being able to capture several German prisioners, including the captain that led the assault. In another German assault on the 14 September, 2nd Lieutenant Gomes Teixeira, of the 7th Infantry Battalion, led a counter attack with his platoon, killing the German commander and other men and capturing four prisoners. Another 2nd Lieutenant, David Neto from the 4th Infantry Battalion, only suported by his orderly, captured an entire German patrol made up of one officer and seven men on the 13 December. For the actions of these officers, the A-Line (Front Line) became known by the Portuguese troops as the "Line of the 2nd Lieutenants".^[9]

These actions also made CEP one of the first units of First Army to comply with General Horne's request for the need to capture German prisioners for obtaining intelligence. This originated a commendation to the CEP from the First Army high command.^[10]

The First Army command recognized that the front of the Portuguese Sector was too long to be defended by only four brigades and reduced it to 12 km on the 22 December 1917. From then on and until the 6 April 1918, it was constituted, from left to right, by the brigade sectors of Fauquissart, Chapigny, Neuve Chapelle and Ferme du Bois.^[11]

Morale was low through the winter of 1917–1918, partly due to bad weather and partly due to a perception among the soldiers that there was no reason for them to be in France. In December 1917, the Portuguese government was brought down; Sidónio Pais was declared to be the new president. The new government called the Portuguese support for the Allies into question and made it easier getting furlough. Many officers used this opportunity. Another factor was that the UK used its whole transport capacity for American troops since April 1917 when the United States declared war to Germany.^[12]

Another major problem was a gradual loss of manpower; by April 1918, 10% of the CEP's strength had become casualties, due to the constant attrition of front-line service, and almost half of the officers were missing. Replacements were not forthcoming, and so units became severely understrength; in order to cope, men were routinely denied leave, and units kept in the frontline for up to six months at a time, further lowering morale.^[13]

From January 1918, the German activity intensified. On the 2 March, a strong German attack is made against Chapigny and Neuve Chapele sectors, with an heavy artillery, gas, mortars and machine-gun fire preparation. At 5am, the Germans assault and take the Front Line, forcing the 4th Infantry Battalion to retreat to the Support Line. The Portuguese artillery reacted, launching about 1400 grenades against the Front Line. A counter attack made by the 4th Battalion, supported by 12th and 17th battalions, terminates the German attack. In this action, the Portuguese having 146 casualties and the Germans having over 200.

Despite the dificulties, CEP, not only withstands the violent activity of the Germans, but even takes the initiative. On the 9 March, under Captain Ribeiro de Carvalho, the 1st Company of the 21th Infantry Battalion, supported by a detachment of 25 sappers, launched a strong assault against the German lines in the Ferme du Bois sector area. In these assault, the Portuguese forces were able to kill and capture a great number of German soldiers and to demolish several enemy fortified positions, suffering themselves 20 casualties. On the 18 March, a company made up of 100 volunteers from the 14th Infantry Battalion, under the command of Captain Vale d'Andrade, assaulted the German positions on the Neuve Chapelle sector, capturing three prisioners.^[14]

CEP continued to have a proactive actitude until the pull back of the CEP's 1st Division. Just three days before that happened, on the dawn of the 3 April, a company of the 2nd Infantry Battalion, under Captain Américo Olavo, assaulted the positions of the German 81st Reserve Division in Chapigny sector, occupying its 1st and 2nd lines and demolishing them, before withdrawing under enemy artillery fire.^[15]

In April 1918, some cases of indiscipline began to be reported from amongst the men. These culminated in the mutiny of the exhausted 7th Infantry Battalion on the 4 April, the men from the unit refusing to return to the frontline, from where they had left just a few days before. The decision was then taken to pull the CEP out of the frontline and replace it with British units. On 6 April, the 1st Division was pulled back,^[16] with the British 55th (West Lancashire) Division extending its lines southwards to fill part of the gap and the 2nd Division taking up the remaining section of the line, now under the operational control of the XI British Corps. The 2nd Division itself, now holding twice the normal divisional frontage, was scheduled to withdraw on 9 April and be replaced by two British divisions. That morning, however, the Germans opposite launched a major attack, which would develop into the Battle of the Lys.^[17]

The morning of 9 April found the CEP's 2nd Division with its 4th Brigade (Minho Brigade) in the frontline at the North, its 6th Brigade at the Center and its 5th Brigade at the South. In a rear position, the 3rd Brigade (left as a reinforcement by the 1st Division) was in reserve.

At about the 4am, the Germans started the Battle of the Lys with a violent bombardment, that lasted about two hours, made by 1700 artillery guns concentrated in front of the Portuguese sector.

At 7am, eight German divisions (8th, 35th, 42nd and 117th Infantry, 81st Reserve, 1st and 8th Bavarian Reserve and 10th Ersatz) attacked the Portuguese line, with a manpower of around 100,000 men against the 20,000 Portuguese defenders.

The 4th Portuguese Brigade (defending the northern sector, with the 8th and 20th infantry battalions in the front line, the 29th in support and the 3rd in reserve) was attacked by the 42nd German Division. The 8th Battalion,reinforced by the 29th, valiantly resisted in the first line to the assault. By the 8am, the left flank of the Portuguese forces started to be enveloped by the Germans, that penetrated by the gaps opened by the collapse of the 40th British Division's 119th Brigade. Under the German pressure, the Portuguese retreated to Laventie (4th Brigade's HQ), where they made the last stand, beeing overran by the 11am.

The 35th German Division assaulted the central sector, defended by the 6th Portuguese Brigade, quickly overruning its battalions in the front line (1st and 2nd battalions).

The southern sector was assaulted by the 1st and 8th Bavarian Reserve divisions. The 8th Bavarian Reserve overruned the 17th Battalion of the 5th Portuguese Brigade in the front line and the 11th Battalion of the 6th Portuguese Brigade, which was in support. The 5th Brigade's 10th Battalion in the front line and the 4th in support were able to hold and slow the progression of the 1st Bavarian Reserve Division. Finally, the 1st Bavarian Reserve was able to reach the 5th Brigade's HQ, overruning it at 1pm, with the brigade commander, Colonel Manuel Martins, being killed in the combat.

By the 10:30am, the Portuguese artillery batteries - which never stopped to fire even after the infantry positions that defended them have been annihilated - started to be overran by the German forces. Most of them were able to resist and continue to fire until 11am.

The bulk of 2nd Division ceased to exist as a fighting formation, retreating in such disarray that the divisional HQ had to relocate twice on 9 April.^[18]

The mounted reserve held by XI British Corps was released to support the 3rd Portuguese Brigade in containing the German advance. The 1st King Edward's Horse and the 11th Cyclist Battalion were sent and joined the 13th (5th Brigade) and 15th (3rd Brigade) Portuguese battalions on the south end of the line, which held their ground until the next morning and prevented any further advances to the south or south-west.^[19] Here occured the famous episode of the 15th Portuguese Battalion's soldier Aníbal Milhais (nickname "Soldier Millions") who, armed only with a Lewis gun, single-handedly defeated two German assaults by laying down intense fire, covering his Portuguese and British comrades, despite coming under heavy attack himself. The last group of these units, under the command of Captain Bento Roma of the 13th Battalion, was able to resist the Germans in Lacouture until the 11:45am of the 10 April.

The main gap in the line was filled by the deployment of the British 50th (Northumbrian) Division and 51st (Highland) Division.^[20]

It was later calculated that the CEP lost 400 dead and around 6,500 prisoners on 9 April, a third of its forces in the front line.^[21]

The — overwhelmingly negative — historical verdict on the battle was epitomized by the comment that the Portuguese "ruined Ludendorff and saved their allies by running away";^[22] whilst the German advance was superficially impressive, especially to begin with, it quickly lost momentum and stalled.^[23] However, it is likely that the collapse would have happened to any unit, not merely the weakened and demoralized Portuguese, as British troops in a similar position the previous month, in Operation Michael, had been overrun just as quickly.^[24]

The reality is that the British high command transformed the Portuguese in the scapegoat to blame for their own faults, trying to ignore the fact that the CEP collapse was only a small part of the general collapse suffered by the British First and Fifth armies before the German Spring Offensive.^[25] There was an attempt to pass the simplistic and dualistic idea that the British units valiantly held the line, while the Portuguese units cowardly fled for the rearguard. The fact that the Portuguese had one third of their men killed or captured - including having all their frontline brigade commanders killed or captured in their HQs - is a simple evidence of the contrary. Had they fled to the rearguard, they could not have been killed or captured by the Germans on the frontline.^[26]

The remnants of the CEP were withdrawn for rear-area pioneer and security duties, though the 1st Division would later be returned to the front line for a short period.

Already under the command of General Garcia Rosado, the remnants of the CEP started to be reorganized in order to reenter combat, in September 1918. The objective was to form three brigades, composed of nine infantry battalions, that were to be organized with the remnants of the former CEP's original infantry units. By the end of October, four battalions were alredy combat capable. These four infantry battalions (I, IV, VIII and IX battalions), together with several artillery, engineers, heavy machine guns and other remaining CEP's units, participated in the Hundred Days Offensive.

The last Portuguese combat action in World War I happened on the same day of the armistice. On the 11 November 1918, under the command of captain Barros Bastos, the 4th Company of the IV Infantry Battalion (former 23rd Battalion of 1st Division) made the last assault against the Germans on the passage of the Scheldt river, Belgium.

By the armistice in 1918, the CEP had lost 2,160 dead, 5,224 wounded and 6,678 prisoners — 14,000 casualties out of an establishment of 60,000.^[27]

• 1st Division
  • 1st Brigade (21st, 22nd, 28th and 34th infantry battalions and a 75 mm light mortar battery)
  • 2nd Brigade (7th, 23rd, 24th and 25th infantry battalions and a 75 mm light mortar battery)
  • 3rd Brigade (9th, 12th, 14th and 15th infantry battalions and a 75 mm light mortar battery)
  • Division troops
    • 3 x Heavy Machine-guns battalions
    • 3 x Artillery battalions
    • 3 x 152 mm mortar batteries
    • 236 mm mortar battery
    • 3 x Miners and Sappers companies
    • Telegraph Company
    • Motor battalion

• 2nd Division
  • 4th (Minho) Brigade (3rd, 8th, 20th and 29th infantry battalions and a 75 mm light mortar battery)
  • 5th Brigade (4th, 10th, 13th and 17th infantry battalions and a 75 mm light mortar battery)
  • 6th Brigade (1st, 2nd, 5th and 11th infantry battalions and a 75 mm light mortar battery)
  • Division troops
    • 3 x Heavy Machine-guns battalions
    • 3 x Artillery battalions
    • 3 x 152 mm mortar batteries
    • 236 mm mortar battery
    • 3 x Miners and Sappers companies
    • Telegraph Company
    • Motor battalion

• Corps troops
  • Cyclist battalion
  • Miners battalion

• Rearguard Base

• Forces under direct command of the British 1st Army:
  • Railway Battalion
  • Heavy Artillery Corps (10 x heavy howitzer batteries)

• www.remembrancetrails-northernfrance.com Portuguese National Cemetery - Richebourg

• Liddell Hart, B. H. (1997). History of the First World War. Papermac. ISBN 0-333-58261-6.

• Rodrigues, Hugo. "Portugal in the Great War". France at War. Retrieved 2008-12-21.

• Pyles, Jesse (2012). The Portuguese Expeditionary Corps in World War I: From Inception to Destruction, 1914-1918. University of North Texas.

• Henriques, M. C., Leitão, A. R. (2001). La Lys - 1918 - Os Soldados Desconhecidos. Prefácio. ISBN 972-8563-49-3.{{cite book}}: CS1 maint: multiple names: authors list (link)