Born in Yorkshire, Gareth grew up in Australia, where he spent a lot of his childhood competing in western riding and showing. He returned to England when he was 23 and started to become involved in dressage, working at Paradise Farm in Oxfordshire. In 1999 he was offered a horse to ride when he met FEI dressage judge and trainer, Stephen Clarke, who he now considers as one of his main influences.
In 2013, Gareth received his first call-up to the senior team with Jane Brewin’s DV Stenkjers Nadonna, coming off the reserve bench to replace Laura Tomlinson. They helped the team win bronze and, a year later, were part of Great Britain’s squad for the World Equestrian Games, where they won team silver.
Following a series of strong results, Gareth was selected to be part of the squad heading to the European Championships with his own, Rebecca Hughes and Julia Hornig's Classic Briolinca. They put in three excellent performances, achieving personal best scores in each round.