He was the son of George Thomas and Lilian Constance Clayton who ran The Stores, Bicknacre. He was born, along with his twin sister Irene Marjorie on 7th June 1921 and baptised at All Hallows, Bromley by Bow on 26th June when George’s occupation was police constable. George had married Lilian Mounter at St Mary’s Church Islington on 11th September 1915. The 1921 census also mentions an older sister Elsie Elizabeth who was born in 1916.
Leonard was educated at Ilford High School and then King Edward VI Grammar School, Chelmsford and subsequently worked as a clerk in the offices of Essex County Council’s Architects Department.
At the age of nineteen he volunteered for the army and was commissioned as a second lieutenant in The Essex Regiment in 1942, gazetted in June of that year. During his training he earned a certificate of merit and was regarded as a promising officer.
On 23rd June 1942 Leonard was acting as platoon commander during a training exercise which involved smoke bombs fired from a 3 inch mortar whilst they were advancing through a wood. The smoke screen was being put down 250 or 300 yards in front of the troops which had been carried out on three occasions but inexplicably on the fourth firing three fell short resulting in Lt Clayton being hit by shrapnel resulting in his spinal column being fractured and he died almost instantaneously. A coroner’s inquest took place at Petersfield where it was suggested that the smoke bombs must have been defective. A verdict of Accidental Death was returned.
Leonard was buried in St Mary’s Church Yard, Woodham Ferrers on 29th June when his coffin, draped in the Union jack, was born by six N.C.O.s from his battalion and there was also a guard of honour. Three volleys were fired over his grave which now has a Commonwealth War Graves Commission headstone.The last post and Reveille were sounded. The Essex Chronicle mentions a long list of mourners who attended the funeral.