David Seath, 31, from Cowdenbeath in Fife, suffered a cardiac arrest three miles from the finish line. He was rushed to St Thomas Hospital by paramedics but died shortly after.
David was running on behalf of Help for Heroes, a non-profit organisation that helps soldiers who have been wounded or injured in line of duty.
Lieutenant Colonel Jon Cresswell, Commanding Officer of 29 Commando Regiment Royal Artillery, paid tribute. He said: “The Regiment was devastated to learn of the tragic loss of Captain Dave Seath during 2016’s London Marathon. Dave was an outstanding commando officer, a natural leader and a true gentleman. He was my Assistant Adjutant and so I knew him very well. He served on operations in Helmand with 19th Regiment Royal Artillery before joining the Commando Gunners and earning his green beret.
David’s parents Libby and Pete, his brother Gary, his girlfriend Gabby Judd, and his aunt Morag paid tribute to him and welcomed donations in David’s memory to his Help for Heroes fundraising page here.