One of four regions referred to as Red Croatia, principality of Zachlumia, was formed lower down the river Neretva, just beneath Pagania. Eventhough the emperor Constantin Porfirogent claimmed Serbian origin to Zachlumians just as Paganians, the prince of Zachlumia, Mihajlo Višević who ruled there in the 10th century had no Serbian descent but that of Litzik's. Before his rule, Zachlumia was not known of. The prince Mihajlo had his residence in the city Ston, at the beginnig of Pelješac Peninsula which was in the early Middle Ages also known as Puncta Stagni. Ston's history goes way back until the 2th century when it was first mentioned as Turris Stagna, while it was known as Stamnes in the 7th century. Somewhere around the 9th century there was formed a Zachlumia (Ston) Diocese, one of the oldest dioceses in Dalmatia, which suceeded to Ecclesia Sarsenterensis and/or Ecclesia Naronitana. Four churches were probably built in the 6th century (Early Christian era) in the field of Ston in the so called Naronitanian ager centuriatus: St. Peter, St. John, St. Mary Magdalene and St. Stephan. All of those churches had been explored by arheologicst, who established that three of them (St. Peter, St. John, St. Mary Magdalene) were adapted in the early Middle Ages, and the fourth one was rebuild in presbytery of the previous church. Somewhere at the same time (the end of the 10th or more likely in the 11th century) was built aisleless domed type St. Michael's church full with the oldest Early Romanesque frescoes on the east Adriatic coast. Church also has many fragmented church furniture, just as the church of Our Lady of Luzine. Eventhough St. Michael's westwerk unfortunatly is not preserved, it is still visible in the ruins of St. Mary Magdalen's church and octogonal type chuch in Ošlje.