Ziguinchor (zi.gɛ̃.ʃoʁ; Siggcoor sigːcɔːr; زيغينكور) is the capital of the Ziguinchor Region, and the chief town of the Casamance area of Senegal, lying at the mouth of the Casamance River. It has a population of over 230,000 (2007 estimate). It is the seventh largest city of Senegal, but largely separated from the north of the country by The Gambia. Unlike the semi-arid to arid north of Senegal, as it is under the influence of the West African Monsoon, Ziguinchor has a tropical savanna climate, with an average annual accumulated rainfall of approximately . There are several competing etymologies for Ziguinchor's name. The most well-known comes from the time when Portuguese traders and explorers came to the region to form a trading post, and derives from Portuguese Cheguei e choram, "I came and they cry". The local people, seeing the Europeans, began crying, thinking they were about to be enslaved. The name, however, likely predates the Portuguese arrival, as the earliest sources mention the Bainuk of Ezigichor. The term may come from the Bainuk language words "asi nin core," meaning "places to go are finished," relating to the end of the Bainuk migrations in their traditional history. It could also come from "ji gi cor," meaning "place of several fields." The first European settlement in the area was founded by the Portuguese in 1645. The Portuguese objective was to form a trading post and a friendship alliance with the local king. The Portuguese objective was trade with the king of Casa (the Casa mansa or king), a loyal friend, described by chroniclers as the mostly friendly kingship towards the Portuguese along the Guinean coast. The king started to live in European manner, with table, chairs and western clothing and, in the court, there were several Portuguese merchants. One of the commodities for trade were slaves, and Ziguinchor became a slave port during much of the Portuguese rule. The spot was not chosen at random.