Eighth Battle of the Isonzo

The Eighth Battle of the Isonzo was the second of three short autumn offensives with which General Luigi Cadorna tried in 1916 to wrest the Karst plateau from the Austrians and open the road to Trieste. Three weeks after the Seventh Battle the Italian 3rd Army of the Duke of Aosta, supported by the southern wing of the 2nd Army at Gorizia, struck again at the same sector of the front, this time after a long bombardment lasting many days. On the afternoon of 10 October the Italian infantry broke into the shattered Austro-Hungarian positions at Lokvica, took the ruins of the village of Nova Vas and for a moment came up to Jamiano. On 11 October, one of the heaviest days of fighting on the Soča, the defenders fell back to the Lokvica–Hudi Log–Lukatić line, and by 12 October both sides were exhausted. Once again the Italians had taken only a scrap of ground, but in three days the Austro-Hungarian 5th Army had lost more than 20,000 men and positions it had nothing to replace with.

Name and dates

In Italian the battle is called the ottava battaglia dell’Isonzo, and Cadorna in his memoirs called it the “second offensive on the Karst”. In German it is the achte Isonzoschlacht. Italian and English-language studies usually date it to 10–12 October, because the main Italian infantry attack began on the afternoon of 10 October. The Austro-Hungarian official history (Österreich-Ungarns letzter Krieg), however, gives the dates 9–12 October: on 9 October, from 6.30 a.m., the whole front on the Karst came under a hurricane of fire, and in the afternoon strong Italian detachments tried in many places to approach the trenches. The Austrian army command at Postojna (Adelsberg) then concluded that the eighth battle had begun. The British chronology of the war, on which our timeline is based, dates the battle the same way, and we keep to these dates, 9–12 October.

Background

On 17 September, when he broke off the Seventh Battle, Cadorna ordered the captured positions to be fortified and everything to be prepared for resuming the fighting as soon as possible. The objectives had not changed. The main blow was again to be struck by XI Corps along the ridge on the northern edge of the plateau, towards the hills of Veliki Hribach, Fajti hrib and Trstelj, and by XIII Corps between the road from Oppacchiasella to Kostanjevica and the lake below Jamiano. This time VIII Corps of the 2nd Army also joined the attack; it was to cross the lower Vrtojbica east of Gorizia and strike at the hills near San Marco. To deceive the Austrians, Cadorna spread rumours of an attack at Gorizia, and in the Tyrol he attacked on the Pasubio to tie down the reserves there. On XI Corps’ narrow four-kilometre sector 66 battalions were packed in, an average of six soldiers per metre of front. Italian critics later compared this mass of troops with Napoleon’s assault column at Wagram.

The Austro-Hungarian 5th Army of General Svetozar Boroević awaited this blow with anxiety. Its positions on the Karst, between Nova Vas and the Vipava, had been completely levelled in September. The soldiers lay behind sandbags and low stone walls, without dugouts, continuous wire or covered communication trenches. Colonel Brosch of the engineer staff, sent to the front by the high command, wrote on 7 October that the defenders “really cover the lines only with their own bodies”, because it was impossible to dig in the hard rock under constant fire, and rock splinters multiplied the losses. The Austrians began building a second line of defence further east, from Fajti hrib through Kostanjevica to the Hermada, but they did not want to give up a single piece of ground on the road to Trieste without a fight. At the same time they had to send troops to other fronts. The German supreme command pressed for reinforcements against Romania, and between 27 September and 5 October three mountain brigades left the Soča for Transylvania. In exchange the 10th Infantry Division was to come from the Tyrol, delayed by bad weather.

Forces

According to the Austrian official history the Italians prepared 221 battalions and 24 squadrons of dismounted cavalry for the attack, of which they used 166 battalions in the battle. East of Gorizia VIII Corps of the 2nd Army attacked with six brigades (37 battalions). On the Karst XI Corps had four divisions in line (the 49th, 45th, 21st and 22nd) and two in reserve, XIII Corps (the 47th, 34th and 33rd Divisions) attacked with 41 battalions on the sector from Oppacchiasella to Lake Doberdò, and VII Corps by the sea with 23 battalions and 24 squadrons. XIV Corps and two more divisions stood in reserve. The number of Italian guns and trench mortars had grown again, though it is not known exactly by how much.

Boroević had 101 battalions on the threatened sector. Between San Marco and the Vipava the 43rd Rifle Division with Galician regiments held the line. On the northern part of the Karst VII Corps of Archduke Joseph August placed three exhausted divisions in line: the 17th and 28th Infantry Divisions and the Hungarian 20th Honvéd Division, reinforced with battalions of the 44th Rifle Division. From Nova Vas to the sea stood the group of General Alfred von Schenk with the 9th and 16th Divisions and a mountain brigade of the Landsturm, in all 30 battalions and 155 guns. The army reserve numbered only nine battalions. The Italians thus again had roughly a twofold superiority in infantry and an overwhelming one in artillery.

Course

The bombardment (30 September – 9 October)

As early as 30 September the Italian artillery began ranging between the Vipava and the sea, and from 3 October the fire grew stronger. By 5 October the artillery battle was in full swing. Heavy shells and trench-mortar bombs smashed the freshly repaired trenches, communication trenches, observation posts and villages far behind the front. According to the Austrian official history, in the first five days of October the defenders of the Karst lost 700 killed and 3,000 wounded, although the Italian infantry had not yet moved. On 6 October rain and fog came, so the Italians postponed the assault, but on 7 October, when it cleared, the fire returned with new force. This time the Italians completely gave up on surprise: day and night they shelled the Austrian positions, aiming to destroy them entirely and wear out the defenders. Trial attacks on hill 208 (7 October) and on Nova Vas (8 October) showed them that this had not yet been achieved.

On 9 October, from 6.30 a.m., the whole front on the Karst came under a hurricane of fire. In the afternoon strong detachments of Italian infantry moved forward in many places, but the thinned trench garrisons everywhere repulsed them. The great assault had not yet come, but the Austrian army command no longer had any doubt that the battle had begun. Cadorna wrote that the bombardment on the Karst lasted all afternoon on 9 October and the morning of 10 October.

10 October

At dawn on 10 October the Italian fire, from the hills east of Gorizia to the sea, turned into a barrage, strongest between the Vipava and the coast at Monfalcone. A cloud of smoke and dust as thick as fog hung over the battlefield. In the afternoon the Italian infantry went forward. At Gorizia three brigades of VIII Corps struck the completely shattered positions of the 43rd Rifle Division between the railway junction at San Pietro (now Šempeter pri Gorici) and the Sober hill. In fighting that went on here until 12 October the Italians took hill 95 and the positions at Sober on a width of about one and a half kilometres, but got no further, and all their attacks across the lower Vrtojbica broke down.

On the Karst the Italian 45th Division dented the front between the ridge on the northern edge of the plateau and Lokvica. The defenders, who had already lost up to half their men during the bombardment, stopped it with the help of the nearest reserves along the field track running north from Lokvica. Further south the Italian 21st and 22nd Divisions failed to break through. The situation became critical, however, between Oppacchiasella (Opatje selo) and the ruins of Nova Vas. Here the remnants of the Hungarian 20th Honvéd Division gave way to the attack of the Italian 47th and 34th Divisions, which occupied the whole position, though afterwards they advanced only cautiously. Cadorna wrote that his infantry had taken the whole line from the Vipava to hill 208, and that Nova Vas, turned by the Austrians into a fortress bristling with machine guns, and the heights around hill 208 fell after particularly fierce fighting. According to the Austrian official history, however, the defenders held, with the utmost difficulty, the trigonometric summit of 208 itself and the stretches of trench adjoining the breach.

Further south things were even more dangerous. Along the road east of Lake Doberdò the Italian 33rd and 16th Divisions routed two battalions of the Austrian 16th Division, then took the ruined trenches on both slopes of hill 144 and approached Jamiano from two sides. Had they pushed on down the valley towards Brestovica, the whole right end of Boroević’s front would have been in danger. It was saved by the remnants of the 102nd Infantry Regiment, which held on to the upper part of the eastern slopes of hill 144 and fired into the Italians’ backs, and by an immediate counter-attack by the reserves. The Italians had to return to their starting positions, leaving many prisoners behind. Lieutenant Theodor Wanke of the 102nd Regiment received for this feat the Knight’s Cross of the Military Order of Maria Theresa, the highest Austrian war decoration. In the evening Archduke Joseph August gave all his reserves to the divisions and ordered them to retake the old positions. Boroević had nothing left to support him with: the first regiment of the 10th Division arriving from the Tyrol could reach the vicinity of the battlefield only the next day.

11 October

The morning of 11 October brought thick fog and relative calm. At first the Austrian counter-attacks succeeded: north of Lokvica the 87th Regiment recovered the lost trenches, and the 20th Honvéd Division, with the help of the 21st Rifle Regiment, came almost back to the old line. Before 11 a.m., however, a new wave of Italian infantry struck. It was stopped only on the Hudi Log–Lukatić line, on the so-called rear position. The old line at Nova Vas was lost for good. Hill 208 was meanwhile held by detachments of the 11th Landsturm Regiment and the 1st Mountain Rifle Regiment; Landsturm Lieutenant Friedrich Tischer received the Knight’s Cross of the Military Order of Maria Theresa for its defence. In the afternoon the Italians attacked north of the road to Kostanjevica, in some places as many as nine times. West of Lokvica the Alpine battalions held their positions despite enormous losses, but a little further north the 87th Regiment again had to give up the trenches it had retaken in the morning. A renewed attack by the Italian 16th Division on hill 144 failed.

Anton Pitreich, head of the operations section at Boroević’s army headquarters, recalled that it was a “terrible struggle” and that 11 October was one of the most memorable days of the great battles on the Soča. The defenders’ losses were already estimated at about 24,000 men, and 41 guns had been put out of action. Boroević had to decide whether, in keeping with the principle of not yielding an inch of ground on the road to Trieste, to try to retake the old line. The reserves were almost used up, and only one regiment of the 10th Division had arrived, which had to be sent to relieve the utterly bled-white 20th Honvéd Division. Boroević therefore gave up the counter-attack. During the night the units of the 28th Division still holding on west of Lokvica were withdrawn to the western edge of the village. The new, continuous line of defence now ran from the edge of the plateau through Lokvica, Hudi Log and Lukatić.

12 October

On 12 October it became clear that the Italians’ attacking strength was also running out. The fighting clearly slackened. The Italians occupied the trenches abandoned by the Austrians and, according to Cadorna, reached the second line of defence east of the Vallone valley, below the western slopes of the Pečinka hill and the first houses of Lokvica and Hudi Log. Late in the afternoon the Italian 45th Division once more attacked the ridge on the northern edge of the plateau in waves echeloned in depth, but accurate fire from the Austrian artillery and mountain riflemen forced it to retreat. In three days this division lost 156 officers and more than 4,000 men. The attacks from Oppacchiasella and Nova Vas and on hill 144 already broke down under artillery fire. In the evening there were a few more local clashes near Bilje in the Vipava valley, at hill 208 and on the hills east of Monfalcone, and then both sides, exhausted, laid down their arms.

Losses

According to official Italian figures, quoted by the Austrian official history, the Italian army lost 657 officers and 19,488 men, but the authors of that history considered these numbers too low. A compilation of Italian infantry losses from other official Italian sources gives 783 officers and 24,404 men, or about 25,000 killed, wounded and missing. Boroević’s army lost 32,000 men on this sector over the whole of October, probably more than 20,000 in the battle itself. Cadorna wrote that the Italians took 8,219 prisoners, including 254 officers, as well as 46 machine guns and 31 trench mortars. They took the most, more than 3,500 prisoners, at Nova Vas. Several thousand Italians were also captured by the Austrians during the counter-attacks. Some studies, including Italian and English-language ones, give higher Austro-Hungarian losses, about 38,000–40,000 men, but the Austrian official history does not confirm such figures.

Significance

The Austrians had once again stopped the Italian offensive. At the point of the deepest breach, at Nova Vas, the Italians advanced less than one and a half kilometres. Their greatest gain was pushing the defenders off the eastern edge of the Vallone valley between Nova Vas and hill 208, but Schenk’s group still held Jamiano and blocked the mouth of that valley. The Austrian official history judged the gains at Sober insignificant. Cadorna proclaimed a success and boasted of the number of prisoners, but Trieste remained as far away as before the battle.

For Austria-Hungary the battle was a warning. The loss of a piece of the fortified line between Nova Vas and hill 208 weakened the defence of the northern part of the Karst still further, where VII Corps now stood on an unfortified line, and on slopes exposed to Italian observers at that. On 16 October Boroević wrote to the high command that his army was in crisis: since mid-August it had lost about 100,000 men in battle, and to defend a sector that four and a half divisions had held in August it now needed eight. He demanded reinforcements, artillery, ammunition, trench mortars and steel helmets to protect against rock splinters. The same day Cadorna ordered the 2nd and 3rd Armies to be ready to resume the offensive from 24 October. Rain and fog delayed it by a week: the Ninth Battle of the Isonzo began on 31 October.