From his base in Fethard, Co Tipperary, the bloodstock tycoon John Magnier has built a genuine multinational operation. Untangling Magnier’s complex corporate empire in 2019, Thomas Hubert identified 75 separate companies spread across ten countries, including entities in Barbados, the British Virgin Islands and Netherlands Antilles. The cornerstones of the empire are Coolmore Stud and Ballydoyle Racing. The former is a world leader in breeding thoroughbreds, while the latter, headed by the racehorse trainer Aidan O’Brien, is among the world’s most successful training operations. Now, the companies behind Coolmore and Ballydoyle are gearing up for a battle in the High…