The nightmare march began in darkness to the dreadful accompaniment of roaring guns and the gentler but no less fearful 'plopping' of gas shells.

Eastern Daily Press: Close-up of the 18th Division memorial.Close-up of the 18th Division memorial. (Image: Archant)

One company at a time, at 15-minute intervals, set off in single file, the men slipping and sliding as sliding as they stumbled forward across the semi-submerged duckboard tracks that snaked for miles across an ocean of glutinous mud.

It took the 8th Norfolks nearly six hours either side of midnight on October 21, 1917 to traverse the 'oozy wilderness' and even then their temporary journey's end brought scant relief.

MORE: The Norfolks' bloody ordeal in the hell of Passchendaele

'The ground,' wrote Lieutenant Colonel Ernest Snepp, 'was a muddy desolation of shell holes and to make matters worse a light drizzle set in.'

Worst off were the men of Captain Arthur Patten's C Company on the right who found themselves trying to prepare for an attack that was barely 3½ hours away on a patch of Flanders earth that was 'nothing but a swamp'.

Exhaustion, however, overcame discomfort and fear. 'In the early morning coldness', the 20-year-old company commander found '75 per cent of the men were sleeping, lying there in open shell-holes with the rain pouring down on them, no greatcoats or blankets, a fair sprinkling of German metal dropping around'.

Patten could scarcely believe what he was seeing. They were 'within an hour of the great Zero hour', he wrote, and 'these men from North Walsham, Fakenham, Holt, Dereham, Cromer, Hunstanton and every corner of Norfolk were sleeping' - or rather 'snoring', as he put it.

Ahead of them in the dripping darkness lay their objective: the last fragments of a shell-wasted village which for nearly a fortnight had marked the bitterly-contested apex of the faltering British offensive east of Ypres.

Like so many of its hapless neighbours, Poelcappelle was no longer recognisable as a human settlement. As the regimental historian observed, 'hardly a brick remained upon a brick' with its poor homes, shops and church reduced to heaps of 'rubbish' that masked a myriad menacing enemy pill-boxes which had thus far defied repeated attempts to capture them.

The ravages of war were even more apparent in the pitted fields surrounding Poelcappelle. There, its one-time girdle of pleasant farms had been ruthlessly 'blotted out', their names surviving only to distinguish what one writer called 'grassless pastures that now grew nothing but machine-guns'.

This was the kind of waterlogged battlefield with which the Passchendaele campaign would forever be associated and which would lead the distinguished British historian A J P Taylor to describe it as 'the blindest slaughter of a blind war'.

By mid-October 1917, after 2½ months of hard fighting in conditions that often beggared belief, it was clear that hopes of a great British breakthrough had, despite some success, been dashed.

The offensive could - and should - have been closed down then, but the commander of the British Expeditionary Force, Field Marshal Haig, persisted in order to gain what he considered to be stronger positions on higher ground in front of his battle-weary troops.

Poelcappelle was the precursor to that final unnecessary struggle. It was a battle fought in what the army's Official Historian called a 'vast wilderness of slime' in which 'hardly a tree, hedge, wall or building could be seen' and in which the resolution of the troops was tested to its very limits.

The attack, spearheaded by the 8th Norfolks, originally a volunteer battalion raised in 1914 as part of Kitchener's new 'citizens' army', followed 48 hours of near unremitting shelling that had added to the destruction.

It was launched at 5.35 am on October 22 when, in Arthur Patten's words, 'to the tick, the whole sky to our rear was lit with the flash of our guns'. Ten seconds later, with bayonets fixed, they were off, amid 'an indescribable din'.

In the final minutes counting down to 'zero hour' Patten had risked edging his men forward about 100 yards to more 'solid ground' that was dangerously close to a diversionary bombardment designed to mask the main thrust.

The advance that followed in the mist and half light of dawn was a fearful effort. 'It was one long scramble down one side of enormous shell-holes, up the other side, splashing through water, struggling through mud,' wrote Patten.

'It was impossible to see more than 20 yards or to recognise individuals, but in the mind of every officer and man there was one fixed determination to keep up with the barrage, in spite of mud, rain, mist and smoke, and to 'do in' any unfortunate Boches [sic], who got between us and our final objective.'

More adverse conditions were difficult to imagine and yet to these obstacles were added 'friendly' shells from a barrage that ought to have lifted but instead inflicted unintended damage, hampering but not stopping Patten's progress.

Given everything on that 'horrible morning', it seemed to one artilleryman watching proceedings from further back 'a perfect miracle that our infantry ever advanced at all'.

But advance they did, against all the odds, until they found themselves in what Patten called 'a perfect village of concrete pill-boxes', many of which had been pulverised by the supporting bombardment.

Those that were still standing resisted fiercely and the battle swiftly resolved itself into a series of close-fought struggles. 'Somehow,' recalled Lance-Sergeant De Boltz, 'we managed to surround these pill-boxes and to crawl up to them and thus avoid their line of fire. We then proceeded to throw Mills bombs down the slits they were firing from and thus cause the Germans to come out of the back entrance… and we were able to take them prisoners [sic].'

Such acts of 'persuasion', as Patten put it, enabled the Norfolks' leading 'columns' to push on towards their objectives 'almost without opposition', leaving the supporting troops with 'the more exciting' task of capturing the machine-gun posts sited in the ruins of the Poelcappelle brewery which represented the enemy's main strongpoint.

The fighting was short and sharp. Patten saw a King's Lynn man 'chuck a bomb into the entrance of a pill-box, 'just for luck', as he put it' and was 'quite overwhelmed' when 16 German soldiers emerged, 'one by one, and implored him to take them as his prisoners'.

At another point where a party of Germans looked like putting up a fight of it, Patten spotted a corporal from Norwich, 'whose rifle was caked with mud, and whose supply of bombs had run out', force their surrender by 'heaving mud at them'.

By 6.50 am the brewery was in Norfolk hands, the 'joyous inspiriting news', as the divisional historian called it, reaching headquarters half an hour later. At much the same time, small parties of men were reported as being visible further forward on the battalion's final objective.

Along the way, they had captured enemy strong-points at Requete Farm, Helles House and a number of nearby concrete emplacements which had been a thorn in the side of the British army for weeks as it 'groped and floundered' in the swamps of Flanders.

So buoyed were the Norfolks that Patten, for one, felt they could have pushed on further and reached even 'more distant objectives'. But, in keeping with the original plan, it was left to another unit, the 10th Essex, to forge on and secure the remaining goals.

'Nobody seemed to care, if even to realise, that he was caked in mud up to his waist, or that his one hour's work that morning represented in energy that of a week in peace time,' observed Patten. 'All they did care was that they succeeded where others had failed, and had struggled through mud and shells to complete victory…'

The success at Poelcappelle, a triumph of planning, training and spirit, cost the Norfolks more than 230 casualties, including more than 70 men killed or missing.

Patten, who had undergone 28 months' continuous service with the battalion and whose courageous leadership was to be recognised by a second award Bar to the Military Cross he had earned on the opening day of the offensive, considered it their greatest achievement of the war.

Writing home, he declared: 'In a long succession of fights on the Somme, the Ancre, at Arras and here in Flanders, the Norfolks have never fought more stoutly and those who gave their lives for their country… on the 22nd at Poelcappelle have really brought lasting peace one decided step nearer.'

A little over a fortnight later the final chapter of the wretched campaign was written when Canadian troops completed, at considerably cost, the capture of Passchendaele and the ridge to which it gave its name.

It proved a pyrrhic victory. The following March the gains made over the course of four months' heavy fighting in which the British and Commonwealth armies suffered nearly a quarter of a million battle casualties were given up without a fight in the space of just three days.

Arthur Patten was not there to witness either the end of the campaign or its inglorious sequel. Shortly after the Norfolks' success, the 'double hero of Passchendaele' was granted 'special' leave and sent home to discover that he was, in the words of his doctor, 'fagged out' from the 'prolonged strain of active service' that had reached a peak during a triumph which one historian likened to 'a beam of light in a dark place'.

Thanks to Dick Rayner, historian of the 8th Norfolks, for his assistance with this article.