1481 Pte James Byrne did serve with the 13th Light Dragoons and enlisted some time before December 1853. He was on furlough from 10 Dec 1853 to 10 Jan 1854 and also from 15 Jan 1854 to 15 Feb 1854. The muster rolls show him AWOL / deserted effective 15 Feb 1854, while a simultaneous muster for the service troops shows him being sent to the Depot (but further records do not record his name). He did not embark for the Crimea and therefore does not appear on the medal rolls for that regiment. I do not have service records for the regiment later than Mar 1856, so do not know if or when he rejoined the regiment. This information appears on page 238 of my book, In Search of the Light Brigade. Hope this helps.