Wilhelm ("Guillermo") Phillip Daniel Schulz was a Hessian-Spanish pioneer in mining and geology. This publication by the Habichtswald Historical and Local Heritage Association is dedicated to Wilhelm Phillip Daniel Schulz (1805-1877), who spent his childhood and youth in the village of Dörnberg (now part of the municipality of Habichtswald in the district of Kassel) and later achieved high honors as a geologist and senior mining official in the Spanish civil service. Scholars and mining experts contribute articles on lignite mining in Habichtswald and on "Guillermo" Schulz as a trailblazer of geology in Spain. Local authors complete the portrait with biographical sketches, results of family research, and descriptions of village life in Dörnberg during the early decades of the 19th century. This publication presents an unusual personality from the region.