estimated Palermo's population at 350,000 around the 11th century, while other historians like Stephan R. Epstein estimated it to be closer to 60,000. Based on al-Maqdisi's statement that Palermo was larger than Old Cairo, Kenneth Meyer Setton put the figure above 100,000 but below 250,000. Traces of the ancient Arab domination can be seen still today. Muslim artifacts include the Kasr ("Castle"), on the cape of the Paleopolis, the district of the great mosque, the Kalsa ("Elected"), the emirs’ seat along the sea, the area of the Schiavoni ("slaves"), crossed by the Papireto river; and, in the western region, the Moasker, the soldiers' quarter. However, the Arab emirate became increasingly torn by inner disputes and was a rather easy prey for the Normans, who had entered Sicily in 1061. In 1072, after four years of siege, Palermo fell to Count Roger I of Sicily, ending Muslim rule there. Normans The Normans restored Christianity as the official religion and declared Palermo to be the capital of the island. In 1130, Roger II was crowned King of Sicily in Palermo. Although Christian, the Normans were tolerant towards the Muslim population, which was a majority in Palermo, but not in Sicily. Jews also remained an important community. However, many mosques were turned into Christian churches. The high level of this multicultural civilization can be seen by the splendour of the new monuments that the new King had built in Palermo. These buildings, which include the church of the Marturana and the Palatine Chapel, show a fascinating mix of Arab, Byzantine and Norman influences. It was under Roger II of Sicily that his holdings of Sicily and the southern part of the Italian Peninsula were promoted, from the County of Sicily into the Kingdom of Sicily; the kingdom was ruled from Palermo as its capital, with the king's court held at Palazzo dei Normanni. Much construction was undertaken during this period, such as the building of the Palermo Cathedral. The Kingdom of Sicily became one of the wealthiest states in Europe, as wealthy as the fellow Norman state, the Kingdom of England. Though the city's population had dropped to 150,000, it became the largest city in Europe, due to the larger decline in Constantinople's population. Sicily in 1194 fell under the control of the Holy Roman Empire. Palermo was the preferred city of the Emperor Frederick II. Muslims of Palermo were migrated and expelled