Source: Michael Doyle Their Name Liveth For Evermore: The Great War Roll of Honour for Leicestershire and Rutland.
He was the son of William Thomas Kinchen, a railway engine driver, born 21st June 1871 in Brize Norton, Oxfordshire and his wife Mary Ann (Polly) Kinchen (nee Grundy, married in the 4th quarter of 1897 in the Blaby, Leicestershire district), born 11th September 1874 in Syston, Leicestershire. William Dennis (Billy) was born on the 28th May 1898 in Wigston Magna, Leicestershire and was baptised on the 11th October 1905 in the Parish Church, Wigston Magna, he had one sibling, John Henry, born 1900 in Wigston Magna, in March 1901 the family home was at 44, Moat Street, Wigston Magna. In April 1911 William was a schoolboy and was residing in the family home at 38, Bushloe End, Wigston Magna, together with his father, a railway engine stoker, his mother and siblings, Frank, born 1902, Arthur Edward, born 1906 and Esther Mary, born 22nd December 1907, the latter three siblings were all born in Wigston Magna. William also had another younger sibling, Dorothy M., born 31st January 1913 in Wigston Magna. William’s Mother died in 1943 in Wigston, Leicestershire, age 68 and his Father died in 1952 in Leicestershire, age 81.
William’s Army enlistment documents do not survive, all that is known of his military service is that he enlisted into the Worcestershire Regiment, being allotted the service number 25316, and was posted as a Private to the 4th Battalion Worcestershire Regiment and with this unit he first entered the theatre of war in the Balkans (Egypt) on the 6th December 1915. He sailed with his Battalion from Alexandria on the 15th March 1916 arriving in Marseilles, France on the 20th March. He was awarded the 1914-15 STAR, British War Medal and Victory Medal.
The War Diary records: 30 May-17 – Order was received to attack and capture enemy post I.25.d.4.8. Heavy thunderstorm at 4:00pm flooded our trenches, mud and water being above our knees in many places. 11:25pm. Attacked as follows 2 platoons in first line. 1 platoon in second. 1 platoon in FINGER TRENCH to carry consolidating material, rations and water to captured position. Attack was immediately observed by enemy at the outset and encountered heavy rifle and Machine Gun fire. Enemy S.O.S. signal went up and an intensely heavy barrage was opened on our trenches. Eventually it was found impossible to advance and the attacking party were brought back to FINGER TRENCH. While re-organising the enemy barrage became more intense than ever and was followed by enemy bombing raid. This was repulsed with loss to the enemy and eventually things became quiet. From documents taken from the enemy dead it was discovered that the enemy had planned an attack on our trenches for the same time as we had attacked. Fortunately we had forestalled them.
Casualties 12 killed, 27 wounded, 2 missing.

Source: Leicestershire War Memorials Project.
WMD Kinchen is recorded at Wigston Peace Garden Memorial as being a casualty of WW2, but this appears to be an error.