In the bright spring of 325 the lakeshore city of Nicaea found itself weighted with a gravity no army had ever brought to its gates. Along the imperial highways came bishops on imperial horses, swaying in curtained wagons, or hobbling on old torture-scarred legs, each bearing a letter sealed with the augustal signet that commanded his presence. They arrived from the rain-washed forts of Britannia, from Iberian ports that smelled of tar, from Cappadocian highlands where winter still clung to the pines. Never before had the Church—once a hunted thing meeting by torchlight in catacombs—been summoned in daylight by the Emperor who ruled the world.