At the time when the boat was sacrificed in the bog at Hjortspring, the first fortified villages appeared. At Borremose in Himmerland and Lyngsmose at Ringkøbing villages have been excavated that show traces of the conflicts of the Iron Age. Both settlements were protected by a defensive ditch. The ditch was densely packed with stakes of oak that had been hammered into the bottom. These were meant to keep attackers from crossing the ditch. The Roman general Caesar also met this type of defence when he conquered present-day France. The stakes in the defensive ditches were given the name “Caesar’s lilies’.