 As the army marched toward the Persian capital, the Sassanids broke the dikes which crossed the land, turning it into marshland, slowing the progress of the Roman army.By mid-May, the army had reached the vicinity of the heavily fortified Persian capital, Ctesiphon, where Julian partially unloaded some of the fleet and had his troops ferried across the Tigris by night.The Romans gained a tactical victory over the Persians before the gates of the city, driving them back into the city.