Modern archaeology is the discipline of archaeology which contributes to excavations. Johann Joachim Winckelmann was one of the founders of scientific archaeology and first applied the categories of style on a large, systematic basis to the history of art. He was "the prophet and founding hero of modern archaeology". The next major figure in the development of archaeology was Mortimer Wheeler, whose highly disciplined approach to excavation and systematic coverage in the 1920s and 1930s brought the science into the modern era. Wheeler developed the grid system of excavation, which was further improved on by his student Kathleen Kenyon. The two constant themes in their attempts to improve archaeological excavation were first, to maintain strict stratigraphic control while excavating (for th