Matadi is the chief sea port of the Democratic Republic of the Congo and the capital of the Bas-Congo province. It has a population of 245,862 (2004). Matadi is situated on the left bank of the Congo River 148 km (92 mi) from the mouth and 8 km (5.0 mi) below the last navigable point before rapids make the river impassable for a long stretch upriver. It was founded by Sir Henry Morton Stanley in 1879.