The 179th Tunnelling Company was one of the tunnelling companies of the Royal Engineers created by the British Army during World War I. The tunnelling units were occupied in offensive and defensive mining involving the placing and maintaining of mines under enemy lines, as well as other underground work such as the construction of deep dugouts for troop accommodation, the digging of subways, saps (a narrow trench dug to approach enemy trenches), cable trenches and underground chambers for signals and medical services. 179th Tunnelling Company is particularly known for its role at L'îlot de La Boisselle and for firing the Lochnagar mine during the Battle of the Somme 1916. The Lochnagar mine formed part of a series of 19 mines that were placed beneath the German lines on the British section of the Somme front to assist the start of the battle.

By January 1915 it had become evident to the BEF at the Western Front that the Germans were mining to a planned system. As the British had failed to develop suitable counter-tactics or underground listening devices before the war, field marshals French and Kitchener agreed to investigate the suitability of forming British mining units. Following consultations between the Engineer-in-Chief of the BEF, Brigadier George Fowke, and the mining specialist John Norton-Griffiths, the War Office formally approved the tunnelling company scheme on 19 February 1915.

Norton-Griffiths ensured that tunnelling companies numbers 170 to 177 were ready for deployment in mid-February 1915. In the spring of that year, there was constant underground fighting in the Ypres Salient at Hooge, Hill 60, Railway Wood, Sanctuary Wood, St Eloi and The Bluff which required the deployment of new drafts of tunnellers for several months after the formation of the first eight companies. The lack of suitably experienced men led to some tunnelling companies starting work later than others. The number of units available to the BEF was also restricted by the need to provide effective counter-measures to the German mining activities. To make the tunnels safer and quicker to deploy, the British Army enlisted experienced coal miners, many outside their nominal recruitment policy. The first nine companies, numbers 170 to 178, were each commanded by a regular Royal Engineers officer. These companies each comprised 5 officers and 269 sappers; they were aided by additional infantrymen who were temporarily attached to the tunnellers as required, which almost doubled their numbers. The success of the first tunnelling companies formed under Norton-Griffiths' command led to mining being made a separate branch of the Engineer-in-Chief's office under Major-General S.R. Rice, and the appointment of an 'Inspector of Mines' at the GHQ Saint-Omer office of the Engineer-in-Chief. A second group of tunnelling companies were formed from Welsh miners from the 1st and 3rd Battalions of the Monmouthshire Regiment, who were attached to the 1st Northumberland Field Company of the Royal Engineers, which was a Territorial unit. The formation of twelve new tunnelling companies, between July and October 1915, helped to bring more men into action in other parts of the Western Front.

Most tunnelling companies were formed under Norton-Griffiths' leadership during 1915, and one more was added in 1916. On 10 September 1915, the British government sent an appeal to Canada, South Africa, Australia and New Zealand to raise tunnelling companies in the Dominions of the British Empire. On 17 September, New Zealand became the first Dominion to agree the formation of a tunnelling unit. The New Zealand Tunnelling Company arrived at Plymouth on 3 February 1916 and was deployed to the Western Front in northern France. A Canadian unit was formed from men on the battlefield, plus two other companies trained in Canada and then shipped to France. Three Australian tunnelling companies were formed by March 1916, resulting in 30 tunnelling companies of the Royal Engineers being available by the summer of 1916.

The 179th Tunnelling Company was formed in Third Army area in October 1915 and moved into the Thiepval-La Boisselle sector of the area of the Somme recently taken over by the BEF. In the Somme sector of the Western Front, local but very fierce underground fighting had taken place in the winter of 1914 and spring of 1915 at La Boisselle, Fricourt, Bois Français and Carnoy. Fowke moved the 174th and 183rd Tunnelling Companies there to relieve the French engineers, but the British did not have enough miners to take over the large number of French shafts and the French agreed to leave their engineers at work for several weeks. To provide the tunnellers needed, the British formed the 178th and 179th Tunnelling Companies in August 1915, followed by the 185th and 252nd Tunnelling Companies in October. The 181st Tunnelling Company was also present on the Somme. Early attempts at mining by the British on the Western Front had commenced in late 1914 in the soft clay and sandy soils of Flanders. Mining at La Boisselle was in chalk, much harder and requiring different techniques. The German advance had been halted at La Boisselle by French troops on 28 September 1914. There was bitter fighting for possession of the village cemetery, and for farm buildings on the south-western edge of the village known as L'îlot de La Boisselle to the French, as Granathof (German: "shell farm") to the Germans and later as Glory Hole to the British. In December 1914, French engineers had begun tunnelling beneath the ruins. With the war on the surface at stalemate, both sides continued to probe beneath the opponent's trenches and detonate ever-greater explosive charges. In August 1915, the French and Germans were working at a depth of 12 metres (39 ft); the size of their charges had reached 3,000 kilograms (6,600 lb). The British tunnelling companies extended and deepened the system, first to 24 metres (79 ft) and ultimately 30 metres (98 ft). Around La Boisselle, the Germans also dug defensive transversal tunnels at a depth of about 80 feet (24 metres), parallel to the front line. No man's land at L'îlot was very narrow, at one point about 46 metres (50 yd) wide, and had become pockmarked by many chalk craters.

In October 1915, the 179th Tunnelling Company began to sink a series of deep shafts in an attempt to forestall German miners who were approaching beneath the British front line. At W Shaft they went down from 9.1 metres (30 ft) to 24 metres (80 ft) and began to drive two counter-mine tunnels towards the Germans. From the right-hand gallery the sounds of German digging grew steadily louder. On 19 November 1915, 179th Tunnelling Company's commander, Captain Henry Hance, estimated that the Germans were 15 yards away and ordered the mine chamber to be loaded with 2,700 kilograms (6,000 lb) of explosive. This was completed by midnight from 20 to 21 November. At 1.30 am on 22 November, the Germans blew their charge, filling the remaining British tunnels with carbon monoxide. Both the right and left tunnels were collapsed, and it was later found that the German blow had detonated the British charge. The wrecked tunnels were gradually re-opened, but about thirty bodies still lie in the tunnels beneath La Boisselle.

At the start of the Battle of Albert (1–13 July), the name given by the British to the first two weeks of the Battle of the Somme, La Boisselle stood on the main axis of British attack. The tunnelling companies were to make two major contributions to the Allied preparations by placing 19 large and small mines beneath the German positions along the front line and by preparing a series of shallow Russian saps from the British front line into no man's land, which would be opened at zero hour and allow the infantry to attack the German positions from a comparatively short distance.

Russian saps in front of Thiepval, Ovillers and La Boisselle were the task of 179th Tunnelling Company. In the front section allocated to the 36th (Ulster) Division, ten saps were run from the British lines into no-man's land north-east of Thiepval Wood. The intention was for each of the ten tunnels to house two mortars.