Complex sentence: The Omnium de Deux Ans was the country's richest race for two-year-olds until 1914, ahead of both the Prix Morny and the Grand Critérium.
Split into simpler sentences: The Omnium de Deux Ans was the country's richest race for two-year-olds until 1914. Its prize fund was greater than those of both the Prix Morny and the Grand Critérium.