Clarence Barker was born on August 21, 1890, in Bradford, Metropolitan Borough of Bradford, West Yorkshire, England. He was the son of Robinson and Mary Jane Barker. He was married to Annie Mabel Sutcliffe. He enlisted in the British Army as a Private in the West Yorkshire Regiment, and later was transferred to the 14th Battalion, Northumberland Fusiliers.

Pvt Barker was reported missing on May 25, 1918, after being taken prisoner. He later died of dysentery on November 19, 1918, while held in a prisoner of war camp near Würzburg, Germany. He is now buried in the Friedhof Niederzwehren, Niederzwehren, Stadtkreis Kassel, Hessen, German.
From https://thorntonbd13.uk/thornton-war-memorials-roll-of-honour-and-war-graves/thornton-war-memorial-and-war-graves/:

Clarence Barker born on 21 August 1890, the son of Robinson and Mary Jane Barker. In the 1891 Census the family was living at 40 Albert Street, Thornton. In the 1901 Census they were living at 9 Granville Place, Allerton. He was baptised at the United Methodist Free Church, Thornton on 31 December 1893. Interestingly his future wife, Annie Mabel Sutcliffe was baptised at the same church a month before him. In the 1911 census they were living at 24 Cobden Street, Allerton, where Clarence, aged 20 was employed as an Apprentice Skep and Hamper maker. In September 1913 Clarence travelled with an Ann Barker on the SS Franconia from Liverpool to Boston, Massachusetts. In February 1914 he travelled on the SS Andania, on his own, from Liverpool to Boston, Massachusetts. On 2 November 1914, at Chautauqua, New York, USA, Clarence married Annie Mabel Sutcliffe. At that point he was employed as a Shipping Clerk, and both were living in Jamestown, New York.
At some stage he enlisted in the British Army as a Private in the West Yorkshire Regiment, #26193, and later was transferred to the Northumberland Fusiliers, 14th Btn, #41639. He was reported missing on 25 May 1918. He was taken as a Prisoner of War. Clarence died of dysentery while in a Prisoner of War camp near Wurtzberg, Germany, on 19 November 1918. Grave reference: III. M. 4., Niederzwehren Cemetery, Kassel, Germany. He is also remembered on Thornton United Methodist Church Roll of Honour., and on the grave of his parents-in-law Richard and Ann Sutcliffe, with his wife Annie Mabel

Source of information: www.findagrave.com, thorntonbd13.uk