The Great Wall seen today was built during the Ming Dynasty, starting around the year 1368 and lasting till around 1640. This new wall was built on a grand scale with longer lasting materials (solid stone used for the sides and the top of the Wall) than any wall built before. The primary purpose of the wall was to make it difficult for semi-nomadic people outside the wall (such as the Mongols under Altan Khan and the Oirats under Esen Taiji) to raid into China with their horses or return with stolen property.