After a slide show on February 19, 1936, of his trip to Bohuslän, a region in southwestern Sweden, Wirth convinced Himmler to launch an expedition to the region, the first official expedition financed by the Ahnenerbe. Bohuslän was known for its massive quantity of petroglyph rock carvings, which Wirth believed were evidence of an ancient writing system predating all known systems. Himmler appointed Wolfram Sievers to be the managing director of the expedition, likely because of Wirth's earlier troubles balancing finances.[1][page needed]