During World War I (1914–1918) the front line crossed the mining concession, with the northern part occupied by the Germans, but despite constant shelling production of coal continued.

The Société des mines de Béthune was constituted on 1 October 1850 to explore for coal in the Pas-de-Calais department.

[2] The owners of the Mines de Béthune acquired shares in this company, and on 13 April 1852 the six partners of Bruay sold to Constant Quentin, Petit-Courtin, Joseph Tellier, Alexis Boitelle and Lobez, in their capacity of president and members of the society of Bethune, all the results of their soundings and their rights.

Sinking of Mine 1 at Bully began on 26 March 1852, and the mine came into operation in 1853..[1] An imperial decree of 15 January 1853 granted the Compagnie de Béthune, created by act of 25 September 1851 and represented by Constant Quentin, Petit Courtin and Joseph Lobez, the concession for coal mines in the communes of Haisnes, Auchy, Violaines, Cuinchy, Beuvry, Sailly, Labourse, Sains, Bouvigny, Aix, Liévin, Loos, Hulluch, Cambrin, Annequin, Noyelles, Vermelles, Mazingarbe, Grenay and Bully in the arrondissement of Béthune, Pas-de-Calais.

[1] At first the company had great difficulty disposing of the products, which had to be transport by horse-drawn carts to Arras, where it could be transferred to barges or railway cars.

[1] Additional mines were sunk between 1859 and 1909 in Vermelles, Loos-en-Gohelle, Mazingarbe, Auchy-les-Mines, Annequin, Sains-en-Gohelle and Grenay.

The company faced many difficulties during his term of office, and had only moderate growth, since neither Plichon nor Boitelle had technical training.

[7] Louis Mercier (1856–1927) was made director-general of the Mines de Béthune in 1877 and became a member of the Comité des forges in 1878.

[7] He became one of the leading industrialists of northern France, president of the Béthune, Blanzy and Sainte-Thérèse mining companies, and a member of a dozen or more boards of directors.

After the first Battle of the Marne from 6–10 September 1914, the "Race to the Sea" established a front line that cut through the mining basin.

[11] From October 1914 to the summer of 1918 the Mines de Béthune were continuously bombarded by German artillery, which destroyed much of its infrastructure.

Only five extraction sites could be kept open, in the communes of Aix-Noulette, Bouvigny-Boyeffles, Bully-les-Mines, Grenay, Mazingarbe, Sains-en-Gohelle and Vermelles.

All types of infrastructure were destroyed including headframes, buildings, rotundas, power stations and railway lines, with work halted while they were repaired.

[12] In September 1917 the Béthune concession was a quadrilateral with an area of 13,500 hectares (33,000 acres) dominated by the summits of Haisnes, Grenay, Bouvigny and Beuvry.

Barricades were built as early as 1916 along the main axes of the mine complex so it could be defended while allowing ventilation and the passage of men.

[11] British soldiers of the 170th Tunneling Company established a listening system at the bottom of shaft 8bis which picked up sounds of activity in August 1917.

After the attack a thick masonry wall was built in the main haulage gallery to isolate the sectors near shafts 8 and 8bis.

[11] The mines were evacuated by order of the military on 12 April 1918, and production resumed only after the final retreat of the enemy forces.

[12] After the armistice of November 1918 the company began to modernise its facilities, gradually replacing steam power by electricity, and developing new methods of extracting coal from the seams.

[1] A monument to the personnel of the mines de Béthune who had died in the war, with bas-reliefs by the sculptor Paul Capelacre, was inaugurated in October 1924.

[13] For industries like metallurgy and coal mining, only a limited company can manage the huge amounts of capital investment required.

[7] Men such as the Plichons, although they did not belong to the rich industrial bourgeoisie, were able to build great fortunes due to their political and technical skills.

[10] Ignace's younger son Pierre Plichon took to the law and became a member of the Paris Court of Appeal, then resigned and joined the board of the Bethune company.

[5] In 1945 the concession was a quadrilateral 6 kilometres (3.7 mi) across with parts of 15 communes: Bully, Grenay, Loos, Vermelle, Mazingarbe, Noyelles, Sains en Gohelle, Auchy-les-Mines, Haisnes, Annequin, Cuinchy, Beuvry, Sailly, Lievin and Aix-Noulette.

[14] The Étoile Sportive de Bully was founded in 1920 by the Company with a sports complex considered the most modern in France.

There were five football pitches, one with stands for several hundred spectators, dressing rooms with showers, individual lockers for players.

Houses built before 1914 are semi-detached, with a simple architectural style, central dormer windows and very discreet brick patterns on the façade.

[16] The Cité des quarante to the west was built for workers in Mine 6 between 1913 and 1927, with a mix of straight and curved streets.

[5] Excavation of Mine 3 in Vermelles began in January 1857, reaching a rugged, steeply inclined deposit of coal at 147 metres (482 ft).

[5] Excavation of Mine 6 at Mazingarbe began in October 1874 and reached an irregular bed of coal at 144 metres (472 ft).