Aalst is a city and municipality in the province of East Flanders in the Flemish Region of Belgium. It is located on the Dender River, about 31 kilometres (19 mi) northwest of Brussels. The municipality comprises the city of Aalst itself and the villages of Baardegem, Erembodegem, Gijzegem, Herdersem, Hofstade, Meldert, Moorsel and Nieuwerkerken; it is the country's tenth largest city by population with 90.068 inhabitants. Aalst is crossed by the Molenbeek-Ter Erpenbeek in Aalst and Hofstade. The current mayor of Aalst is Christoph D'Haese, from the New-Flemish Alliance party. The town has a long-standing folkloric feud with Dendermonde, north along the same river, which dates from the Middle Ages.