Turf wars and machiavellian siblings often make for compelling corporate drama on screen, think HBO’s Succession or Ridley Scott’s House of Gucci. These slickly produced stories where sins of greed and wrath are wrapped in blood lines and cashmere baseball caps have captivated audiences for centuries, just swap out the cap for a crown and look to King Lear or Oedipus Rex. But battles over a family business are not confined to fiction. The dynasties of Ireland have long taken their kitchen table arguments to the pews of the Four Courts. With legacy, money and lifelong relationships and tensions at stake,…