After the Council of Constance in the 15th century, the alternative name "Lacus Constantinus" was used in the (Roman Catholic) Romance language area. This name, which had been attested as early as 1187 in the form "Lacus Constantiensis", came from the town of Konstanz at the outflow of the Rhine from the Obersee, whose original name, Constantia, was in turn derived from the Roman emperor, Constantius Chlorus (around 300 AD). Hence the French: "Lac de Constance", Italian: "Lago di Costanza", Portuguese: "Lago de Constança", Spanish: "Lago de Constanza", Romanian: "Lacul Constanța", Greek: "Λίμνη της Κωνσταντίας – Limni tis Konstantias". The Arabic, بحيرة كونستانس "buħaira Konstans" and the Turkish, "Konstanz gölü", probably go back to the French form of the name. Even in Romance-influenced English the name "Lake Constance" gained a foothold and was then exported into other languages such as Hebrew: ימת קונסטנץ "yamat Konstanz" and Swahili: "Ziwa la Konstanz". In many languages both forms exist in parallel e.g. Romansh: "Lai da Constanza" and "Lai Bodan", Esperanto: "Konstanca Lago" and "Bodenlago".