New Constantinople was a city-state on Riverworld, founded and ruled by Alexios Komnenos as basileus and his brother, Isaac, as kaisar, and located along a stretch of the River. An Eastern Orthodox state, New Constantinople was populated primarily by Rhomaioi or Hellenized citizens of the empire historians came to call the Byzantine Empire. There was also a minority of Egyptian peasants from the time of Ptolemy III, who had accepted Christianity, and became in some ways more loyal than Alexios' fellow Rhomaioi.
New Constantinople was bordered by red-skin pagans up-river who only wanted to be left alone. Down-river was the Muslim city-state of Bornu, ruled by Sultan Musa ar-Rahman. As Alexios was far more worried about Bornu, he left the pagans alone.
As time passed, it soon became clear that New Constantinople and Bornu would be at war. However, Alexios realized that, while none of his men would truly die, they would be resurrected elsewhere on the River, and so New Constantinople would still lose them. Thus, he resolved to form an alliance with with Mayor Richard J. Daley of Shytown, a community which lay down River of Bornu. After concluding a pact, New Constantinople and Shytown jointly attacked Bornu.
Alexios' Rhomamoi swept over the border into Bornu. The more disciplined men of New Constantinople quickly overwhelmed the Bornu. Outside the royal palace, Musa himself challenged Alexios to the death. However, Musa was immediately attacked by Alexios, Isaac, and several others. Musa was killed, but Alexios allowed his surviving men to surrender. Not long after, the army of Shytown, which had launched their attack at about the same time, marched triumphantly into the capital. The victors the divided up Bornu's assets.