William John Tucker was born in 1897 at Castle Street, in Tiverton, Devonshire, the eldest of eight known children to John William Tucker, a labourer, and Martha Tucker (formerly Blake). He was baptised on 25 July, 1897, at St. Peter's Church in Tiverton. He had two brothers and five sisters: Phyllis Ellen (1900); Alma Elizabeth (1902); Lillie (1904); Edith (1906); Mildred Emma (1908); Francis Walter (1910); and Herbert Blake (1913). In 1901 the family lived at 2 Sanders Court, Castle Street, in Tiverton, and were living at the same address ten years later, by which time the father was a coal merchant's carter, and the young William was a 13-year-old draper's errand boy.

William John Tucker's service record has not survived, and what is known has been extrapolated from other sources. He enlisted at Perham Down, in Wiltshire, and joined the 1/4th Battalion (Territorial Force), of the Devonshire Regiment, as a private, no. 2596, although the medals roll states his unit as the 2/4th Battalion. The 2/4th Battalion mobilised at Exeter in September, 1914, as part of the 2/Devon & Cornwall Brigade, 2/Wessex Division. In December, 1914, it embarked at Southampton for India, where it arrived in January, 1915. It did not leave India, for Egypt, until October, 1917. The likelihood is that Private William Tucker was posted either with or to the 2/4th Battalion in India, from where he was transferred in a draft of reinforcements to the 1/4th Battalion in Mesopotamia. The 1/4th Battalion mobilised at Exeter in August, 1914, as part of the Devon & Cornwall Brigade, Wessex Division. In October, 1914, it sailed for India, and landed at Karachi the following month. It then came under the orders of 3rd (Lahore) Divisional Area at Ferozepore, and in February, 1915, it moved to the independent 42nd Brigade of the Indian Army. In March, 1916, it landed at Basra, in Mesopotamia, with the independent 41st Indian Brigade and thereafter remained in Mesopotamia for the rest of the war. In May, 1916, transferred to 37th Brigade in 14th (Indian) Division. By November, 1916, the battalion was in the Sinn area conducting training, where it remained until 13 December. The intention was then to secure the entrenched position at Hai, and over the coming days the battalion was engaged in activities in preparation and on 19 December crossed the Shatt-al-Hai, with the 37th Brigade forming 'C' Column. The war diary notes that on 23 December the arrivals included 4 other ranks from the 2/5th Devon's and 2/4th Devon's. During the remaining days of 1916 reconnaissance was carried out and working parties provided, before the brigade took over a new line at Nahr Bassouia.

Into January, 1917, the battalion continued to provide working parties, with information received that the enemy had constructed new trenches. On 8 January, 1917, an order set out the forthcoming operations, and the battalion moved off the next day. The forward units captured the Turkish trenches capturing many prisoners, which the battalion followed up and then provided working parties. On 14 January the battalion took over the picquet line and furnished patrols and working parties, which continued until 21 January, when the battalion was relieved and returned to the Brigade Camp. On 23 January orders were received outlining forthcoming operations against the Hai Triangle. The orders were then cancelled owing to the state of the ground after heavy rains were experienced. The operation then commenced on 25 January and at 10.45 am it was reported that the enemy trenches had been occupied with few casualties. The Turks then counter-attacked but were driven back. Operations continued steadily, despite some hard fighting, over the remaining days of January, and on 28 January the brigade took over the Hai trenches, with the 1/4th Battalion in Emperor's Trench, and to move up to Queen's Trench and King's Trench when the Gloster's, who occupied them, moved out. The battalion occupied the trenches at 8.30 pm. On 29 January the battalion suffered one other rank killed and one officer and 14 other ranks wounded. On 30 January the battalion occupied the second line of trenches and suffered 2 other ranks wounded, with 3 wounded the next day. Total casualties for the month of January were one other rank killed; one officer and 19 other ranks wounded; with 2 officers and 57 other ranks evacuated sick. On 1 February, 1917, the battalion received orders that an attack would be delivered at 12.10 pm, and that it was to be at readiness once the attacking brigade was in the enemy's trench. The attacking units, having gained the enemy trench were unable to maintain it and had to withdraw. The 1/4th Battalion then stood by all day. A further operation order was received, with the 37th Brigade ordered to capture a double line of trenches, with the assault delivered by the 1/4th Devonshire's and 1/2nd Gurkhas, from their first and second line trenches. At 7.30 am on 3 February, 1917, 'A' and 'C' Companies moved to the right along Gunning Trench, whilst 'B' and 'D' Companies moved across Matthew Trench. At 10.30 am the 1st Line left Gunning Trench and proceeded about 30 yards and lay down in the open. At 10.38 am the assault was delivered in eight waves at 30 paces intervals. As they approached the first line of trenches they were hindered by their own artillery. Once the barrage lifted they went right on to the second trench and consolidated, with the bombers clearing the front trench. They were then determined to go on, over a nullah and into the open, and came under fire from their own artillery, which caused over 50% of the casualties. When the barrage lifted the men got into the Turkish trenches and inflicted heavy casualties. There the companies re-organised and held the nullah for the night until relieved. The battalion went into the attack with 15 officers and 403 other ranks, of which only 5 officers and 186 other ranks returned unscathed. The officers lost 4 killed and 6 wounded, with the other ranks losing 63 killed, 149 wounded and 5 missing. Private William John Tucker was one of those killed in action at the Hai Salient on 3 February, 1917. He was aged 19, and was initially buried at a battlefield site.

William John Tucker's body was subsequently exhumed and reburied, where he lies in the Amara War Cemetery, in Iraq, with his grave marked by a CWGC headstone. This cemetery was destroyed during the Iraq War, and, at the time of writing, is waiting to be re-built. He is also commemorated on the War Memorial Hall at Tiverton, in Devonshire, as well as on the war memorial within St. Peter's Church in Tiverton.

William John Tucker's service earned him the British War Medal, 1914-20; and Victory Medal, 1914-19.