added by archaeologs Danish prehistorian and paleontologist who succeeded Christian Jurgensen Thomsen as Director of the National Museum of Denmark in 1865. In the field, Müller improved the techniques of excavation, particularly in recognizing stratigraphic relationships. Müller developed new techniques of excavation and monument preservation and supported the principle of the influence of Mediterranean civilization on northern Europe. He built detailed typological sequences and cross-dated them by reference to the historical calendars of the Near Eastern civilizations. He was aware of the possibility of variation in culture among contemporary groups and suggested, for instance, that there were several contemporary versions of the Neolithic of northern Europe. During the late 19th century, he discovered the first of the Neolithic battle-ax cultures in Denmark.