Bastiaan Johannis "Bas" van der Vlies (Sliedrecht, June 29, 1942) is a Dutch politician. He is member of the confessional Political Reformed Party (SGP), and a member of Dutch Parliament since June 1981. Since 1986, he is also parliamentary leader of the party. Sliedrecht (population: 23,837 in 2004) is a town in the western Netherlands, in the province of South Holland. ... June 29 is the 180th day of the year (181st in leap years) in the Gregorian Calendar, with 185 days remaining. ... 1942 (MCMXLII) was a common year starting on Thursday (the link is to a full 1942 calendar). ... A politician is an individual who is a formally recognized and active member of a government, or a person who influences the way a society is governed through an understanding of political power and group dynamics. ... The Staatkundig Gereformeerde Partij (SGP, literally Constitutional Reformed Party) is a Dutch constitutional theocratic political party following conservative Christian principles, in the tradition of the Dutch Reformed Church. ... The Tweede Kamer (second chamber) is the lower house of the Staten-Generaal, the parliament in the Netherlands. ...

Van der Vlies obtained a hydraulic engineering degree from the Delft University of Technology. He worked as a math teacher before becoming a politician. He is currently the most "senior" member / parliamentary leader of Parliament, having already spend more than 25 years there. Frans Weisglas, who is the president of Parliament, is a close second, but does not lead his parliamentary faction for obvious reasons. Hydraulic engineering is a sub-discipline of civil engineering concerned with the flow and conveyance of fluids, principally water. ... Founded in 1842, the Delft University of Technology, in Delft, the Netherlands, is one of the oldest, largest, and most comprehensive technical universities in the Netherlands, with over 13,000 students and 2,100 scientists (including 200 professors). ...