Born at Balby in 1898, Dennis was the youngest son and one of nine children of Dennis and Frances (Fanny) Richardson (nee Porter). His father, born in Thorne although brought up in Crowle, was a bricklayer and his mother was from Marholm in Northamptonshire. From 1901 the family lived in Watson Row, North Street and in 1911, Dennis had followed his father into the building trade as an apprentice joiner. He was also the brother-in-law of Albert Wilson who married his elder sister Emma.
Dennis enlisted in the King’s Own Yorkshire Light Infantry at Goole probably after 1915. It is not certain when he went out to France but he was certainly with the 1/5th KOYLI when it was absorbed into the 1/4th KOYLI under the army reforms of February 1918.
In April 1918 the 1/4th KOYLI were south of Ypres defending the village of Neuve Eglise (Nieuwkerke) which lay on the road to Kemmel when the German Army launched its Spring Offensive, Operation Georgette towards that area. On 11th April the village was at the centre of their attack and the 1/4th KOYLI suffered heavy casualties in the three days of fighting, part of the Battle of Bailleul, they spent defending the village.
Following Neuve Eglise the 1/4th KOYLI were taken out of the front line to rest and recover. On the 25th April they were in Toronto Camp, south of Poperinge, when it was shelled by enemy artillery causing them several casualties. Evacuating the camp to positions south of Ouderdom, here they were machine-gunned and bombed by enemy aircraft.
That evening the battalion received orders to move back to the front to participate in a counter-attack the following morning, leaving Ouderdom around 1.00am. The attack began at 4.25am but almost immediately the attackers were halted by heavy machine gunfire and were forced to retreat. Throughout the rest of the day they came under more heavy artillery fire and had to face a large-scale enemy infantry attack, which they fought off with difficulty, gaining more casualties. The following two days also saw further attacks and casualties before the 1/4th KOYLI were relived.
In the whole of this operation, part of the Second Battle of Kemmel, the 1/4th KOYLI lost 77 men killed, 340 wounded (13 of whom would later die) and 93 missing. One of the missing was Dennis Richardson. He has no known grave and is commemorated on the Tyne Cot Memorial.