John was baptized on 13-Nov-1898 in St. Andrew's Dublin City parish. He was the son of John P. Shiel of Kilbegnet House, County Roscommon.
Second Lieutenant John Hubert Trevor Shiel was killed in action on 08-Mar-1918. He was in the Dorsetshire Regiment, First Battalion. He was memorialized in the Canada Farm Cemetery in Ypres, Arrondissement Ieper, West Flanders, Belgium.
Sources
Baptism record, John Hubert Trevor Shiel, 13-Nov-1898, St. Andrew's Dublin City Parish, Dublin Diocese, County Dublin. National Library of Ireland, Microfilm 09498/04, page 102 [1]
Baptism Record for John Hubert Trevor Shiel; Birth Date: 04-Nov-1898; Baptism Date: 13-Nov-1898; Baptism Place: Westland Row, Dublin, Ireland; Father: John Shiel; Mother: May Bramwell Davis. E-Celtic; Dublin, Ireland. Ancestry.com. Ireland, Select Catholic Birth and Baptism Registers, 1763-1917 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2014.
"England and Wales Census, 1901," database, FamilySearch (https://familysearch.org/ark:/61903/1:1:X986-1PD : 20 May 2019), John H T Shiel in household of Annie E Green, St Marylebone, Middlesex, England, United Kingdom; from "1901 England, Scotland and Wales census," database and images, findmypast (http://www.findmypast.com : n.d.); citing Rectory subdistrict, PRO RG 13, The National Archives, Kew, Surrey.
British and Irish Military Databases. The Naval and Military Press Ltd. Military-Genealogy.com, comp. UK, Soldiers Died in the Great War, 1914-1919 [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2008.