Battle of the Lys (1918)

Background

Ludendorff's first spring offensive, Michael, had driven the British back across the Somme from 21 March, and a second blow near Arras, Mars, failed on 28 March. The German high command had long studied an attack in Flanders, St George, from the La Bassée canal to Ypres. Michael had swallowed the divisions it needed, so it shrank to Georgette: the Sixth Army would break the Portuguese sector of the Lys plain, widen the breach north towards Armentières and drive on the rail junction of Hazebrouck, with the Fourth Army joining in against Messines ridge.

The aim was to break the British First Army, push the Second Army aside to the north and drive west to the Channel, cutting the BEF off from Calais, Dunkirk and Boulogne. The British could give little ground here: the front line lay barely fifty miles from the coast, with the depots, aerodromes and hospitals of Flanders crowded behind it.

The low, waterlogged plain had been thought too wet for a major attack before May, and the sector had been quiet since the winter of 1914–15. But the spring of 1918 was unusually dry. The British divisions sent to rest there had been shattered on the Somme and refilled with recruits. The two-division Portuguese Corps had been run down by months without reinforcements, and its 2nd Division was holding with three brigades a front the whole corps had once held with four. On the afternoon of 8 April the division was ordered to withdraw for a long rest, with a British relief due on the night of 9/10 April. Its men spent the night packing. How much the British command knew of the coming attack, and how much it told the Portuguese, is still disputed.

The armies

Under Ludendorff's direction, Crown Prince Rupprecht's army group attacked with General von Quast's Sixth Army south of Armentières and General Sixt von Armin's Fourth Army to the north, with Colonel von Loßberg as its chief of staff. Both had many stormtroops trained in infiltration. On 9 April eight divisions attacked in first line with six behind, none of them used in March. Four divisions faced the three weak Portuguese brigades. Colonel Bruchmüller, who had planned the 21 March bombardment, ran the Sixth Army's artillery, with only nine days to prepare instead of seven weeks.

General Horne's First Army held the Lys plain. In XI Corps (Haking) the 55th (West Lancashire) Division, rested after Cambrai and drilled in counter-attack, held 4,000 yards at Givenchy with nine battalions. The Portuguese 2nd Division under Gomes da Costa held 10,000 yards with sixteen. XV Corps had the 40th and 34th Divisions, nine battalions each on 7,500 yards. The water table ruled out trenches, so men fought from breastworks, fortified farms and wired hedges, between dykes too wide to jump. The Portuguese were also unsure of their task: Haking insisted on holding a main line at all costs, while the Portuguese had trained for defence in depth, and Gomes da Costa later argued that his worn battalions had been asked to hold too many lines. Plumer's Second Army held Messines and the Ypres salient to the north, with the Belgians beyond. From mid-April the French sent the Détachement d'Armée du Nord under de Mitry.

The battle

Estaires, 9–11 April. CDB90 records the whole battle as one engagement, Lys (332). On 9 April mist cut visibility to forty yards. At 4.15 a.m. a gas and high-explosive bombardment fell on headquarters, batteries and roads from Givenchy to Laventie, and the Portuguese division's headquarters at Lestrem was hit by the first shell. German patrols slipped through gaps before the assault went in at 8.45 a.m. (Portuguese accounts say 7 a.m.). Portuguese troops were already drifting back by 7.30. Some posts held: Richebourg-l'Avoué and Neuve Chapelle until nearly 11 a.m., the 10th Regiment until trench mortars had killed most of its men, and La Couture, which Portuguese writers single out, along with Private Aníbal Milhais and his Lewis gun. By 11 a.m., though, the division had broken as a formed body, and the Germans claimed 6,000 prisoners. Cyclists, King Edward's Horse and brigades of the 51st and 50th Divisions were rushed to the Lawe. At Givenchy the Germans reached the ruined church by about 10 a.m., but the 55th's counter-attack platoons restored the line by midday, and a rehearsed flank faced north. The 40th Division gave way. By nightfall the Germans had broken a 15 km front and reached Estaires on the Lys.

Messines, 10–11 April. The Fourth Army attacked north of Armentières with four divisions and took Messines. Armentières, now in a salient, was evacuated on 11 April and Merville fell. That day Haig issued his Special Order: 'There is no other course open to us but to fight it out. Every position must be held to the last man: there must be no retirement. With our backs to the wall and believing in the justice of our cause each one of us must fight on to the end.'

Hazebrouck and Bailleul, 12–15 April. On 12 April, the most critical day, tired and intermixed units with junior officers in command fought on a shifting front, often without their own artillery. The 1st Australian Division came up by train to cover Hazebrouck and threw back the first attack shortly after midnight on the 13th. The 4th Division held Hinges ridge and the 5th Nieppe forest. On 13 April 23 German divisions in front line and nine in second faced 14 British divisions, four of them reduced to cadres, and gained little. Bailleul fell on 15 April. Plumer shortened his line, leaving only outposts on the Passchendaele ridge won the previous autumn. Meteren and Wytschaete fell on the 16th.

First Kemmel, Béthune and Merckem, 17–19 April. On 17 April attacks on the Kemmel hills were cut down by machine guns firing in enfilade, the Belgians threw back an attack at Merckem, and the Australians beat off two assaults. On the 18th a push on Givenchy, Festubert and Béthune failed. By 21 April French divisions had relieved IX Corps on 11,000 yards of front around Kemmel.

Second Kemmel, 25–26 April. The bombardment opened at 2.30 a.m., and at 6 a.m. three and a half German divisions attacked the French on Kemmel. The Alpine Corps' Leib Regiment was on the summit by 7.10, before the French supports were out of their dug-outs, and took 800 prisoners. A Franco-British counter-attack at 3 a.m. on the 26th failed.

Scherpenberg, 29 April. The last big attack, towards the Scherpenberg and Mont Rouge, ran into a defence organised in depth. That evening Loßberg advised stopping the offensive, and Ludendorff agreed.

Aftermath

British losses for 9–30 April came to 82,040 gross, or about 76,300 after missing men who returned were deducted. French losses were 30,000–35,000, and German estimates run from 86,000 to 109,300. The Germans had driven a salient up to 15 km deep and taken Kemmel, but not Hazebrouck, Cassel or Mont des Cats. Loßberg concluded that the Fourth and Sixth Armies had exhausted their powers of attack. General von Kuhl judged that the second great offensive had not brought the hoped-for decision, and the German high command turned next against the French. The ground at Passchendaele, bought so dearly in 1917, was given up in days.

The battle left a long shadow in Portugal. After it the British command blocked the rebuilding of the Portuguese Expeditionary Corps as a front-line force. British writers were often scathing about their 'ancient ally', while Portuguese accounts dwelt on La Couture and Milhais and presented 9 April as an epic stand against impossible odds. The army used that suffering to justify a growing role in politics, which ended in the coup of 28 May 1926. Deaths were in the low hundreds; prisoners passed 6,000. Older Portuguese figures of over 1,300 killed are now thought inflated. 9 April is still marked at Batalha monastery.

Chris Baker calls the Lys a neglected battle. He argues that a string of Allied defensive successes, together with the German army's lack of mobility, decided it.

Wargaming it

The Lys suits two scales. On the operational level, a division or brigade game on the plain from Givenchy to Bailleul, in roughly half-day turns, makes the battle a race. The Germans must get across the Lawe and the Lys and reach Hazebrouck before the British, Australian and French reserves arrive by train and lorry. Roads should matter enormously: the clay turned to glue, most roads carried one-way traffic only, and dykes and hedges made cross-country movement slow. Bridges captured intact, as on 9 April, should be a real prize.

On the tactical level, Givenchy on 9 April is a superb defensive scenario at company scale. The 55th Division had keeps, concrete machine-gun posts and a 300-yard tunnel with dug-outs for two battalions, and drilled counter-attack platoons. Forty-yard mist, gas masks for the first hours, and an open northern flank once the Portuguese front gave way should all be in the rules. Kemmel on 25 April is a sharp single-hill assault, with mist, a short bombardment and defenders caught below ground.

Portuguese morale needs care: give the 2nd Division the burdens the sources describe (depleted battalions, a muddled mission, a relief half done) rather than a blanket penalty, and let some posts hold. What-ifs: the Portuguese relieved a day earlier; Haking's reserves sent to the right place in time; Hazebrouck falling on the 12th; Ludendorff committing the divisions he kept back.

Maps and pictures

Pictures from the time

Photographs by the armies' photographers and the press, and drawings made at the time: free-to-use pictures from the battle's category on Wikimedia Commons. Each opens its file page there, with the full caption and source.