Theiler founded CSI in 1988 with his brother Urs, together the pair used their own startup capital of roughly
CHF 2 million to launch their first event, which attracted 21,000 spectators on its debut. According to Bilanz, today CSI is the largest and most lucrative indoor equestrian tournament in the world, with over one million spectators worldwide. It also hosts the
Grand Prix show jumping championship televised live by FEI TV.
Mercedes-Benz has been a joint partner and sponsor of CSI since inception, other partners include
Formula 1 Sauber,
LGT,
SRF,
Tages Anzeiger and
Longines. == Equestrian achievements ==