The date for the battle was finally set for 25 September 1915 and on the 21st the British artillery commenced its four day preparatory bombardment - firing off a quarter of a million shells.
In Belgium a feint attack would be made at Bellewaard on the 25th to confuse the German commanders.
Bellewaard 25 September 1915
On the eve of battle the weathermen finally gave a positive forecast for the wind, it was up to Haig to make his decision as to which plan he was going with.
At 05:00 hours Haig watched the smoke drifting away from one of his staff officers cigarettes and chose to go with the gas.
At 05:50 hours the gas was released and at 06:30 hours the 1st Army climbed out of its trenches and attacked the German lines.
On the southern end of the battlefield the 47th (London Territorials) Division had the task of attacking towards the Double Crassier a huge mound which dominates, even today, the main Bethune - Lens Road
To their left the 15th (Scottish) Division would attack Loos village and the ridge behind it, known as Hill 70.
Piper Daniel Laidlaw VC
Next in line was 1st Division who were attacking towards the village of Hulluch.
All three Divisions had the advantage of the gas cloud and their attacks went well. Loos fell to the 15th Division after a night of street to street fighting and the 1st Division advanced well, taking in ground now occupied by St Mary's ADS Cemetery on the outskirts of Hulluch.
To the north however the gas had turned into an own goal. The gas officers were against using the weapon but the Corps Commander General Horne insisted. The gas was released but the strength and direction of the wind either didn't move the gas or just blew it back into the faces of the soldiers in their own trenches.
The British were wearing rudimentary gas masks which basically consisted of a hood with eye holes - they were very uncomfortable to wear and themselves made breathing difficult. Many soldiers decided to take the chance with the gas rather than the incapacitating gas mask.
The attack by the 2nd, 9th (Scottish) and 7th Divisions faltered to a halt in the face of withering machine gun fire from the German positions, though a hold was gained on the Hohenzollern Redoubt near the Cité Madagascar (and close to where you will now find Quarry Cemetery).
The Hohenzollern Redoubt proved to be the sacrificial stone of the 46th (North Midland) Division who attacked it in the closing days of the Loos Battle. In the end it would remain in German hands until their withdrawal at the end of the war.
The gains on the southern side of the battlefield were tending to give the British the upper hand as a hole had been driven into the German lines. Success needed to be bolstered - reserves were needed.
As already stated the two Reserve Divisions (21st and 24th) had remained under the command of Sir John French as opposed to being immediately available to Haig who was running the battle.
Over two days these two Divisions had marched 60 kilometres on the French cobbled roads towards the front line. Both Divisions were made up of volunteers from Kitchener's New Army, men who had answered the call, that their country needed them, but had no other real practice in the arts of war save their initial training. They had been in France a matter of weeks and were now expected to take on well emplaced and defended German positions.
They spent the eve of the battle marching in the pouring rain up to the front line, but by the time that they got there they were too tired to be of much use and it was too late in any case.
German reserves had been closer to hand and they swiftly sealed up any holes in their secondary lines and re-wired those areas that had been wrecked.
On the 26th the raw recruits of the 21st and 24th Divisions continued the assault on the German lines, but without the aid of surprise and without the aid of gas.
Although conducted with great gallantry their attacks were beaten off by the Germans and counter attacks threatened to retake positions gained on the first day.
The German defenders were not so much taken by surprise that a second assault on their positions was made, but rather by the fact that over open territory it would even be contemplated.
The German machine guns cut down the men from Kitchener's Army in swathes, the carnage becoming so bad that the gunners eventually stopped firing to allow the British to withdraw and take their wounded with them.
On the 27th the Guards Division finally arrived and they shored up the line until it stabilised. It was during their attacks near Hill 70 that Lieutenant John Kipling of the Irish Guards and only son of the writer Rudyard Kipling went missing.
Although in theory the Battle of Loos continued until 18 October in effect it finished after three days.
To the south, Vimy Ridge held out against the French and remained in German hands until stormed by the Canadians and British in April 1917.
British casualties were about 50 000 killed and wounded and included over 2 000 casualties from their own gas. Many of the fallen would never be found and their names are inscribed on the walls of the Loos Memorial at Dud Corner Cemetery.
Recriminations about the handling of the reserves would lead to Field Marshal French's dismissal and replacement by General Haig. French stated that he had handed them over to Haig's command early on the morning of the 25th. Haig produced the paperwork to show that in fact the transfer had only taken place in the afternoon - far too late to be used as the knockout punch that he badly needed.
Recriminations about the number of shells available and the number that failed to explode (Thus Dud Corner Cemetery) would bring down the government.
Loos was an almost win. When the tally had been made, it lived up to its French pronunciation - a bloody loss.
The Lone Tree
The following is a list of some of the cemeteries in the general area