VELSEN, THE NETHERLANDS—The Guardian reports that traces of a Roman fort first spotted by schoolchildren in 1945 in the Netherlands on the banks of the Oer-IJ River have been studied by a team of researchers led by archaeologist Arjen Bosman. The camp is thought to have been established between A.D. 12 and 41 by the emperor Caligula and developed by his successor Claudius for the successful invasion of Britain in A.D. 43. “We know for sure Caligula was in the Netherlands as there are markings on wooden wine barrels with the initials of the emperor burnt in, suggesting that these came from the imperial court,” Bosman said. The thousands of Roman soldiers stationed in the Netherlands would have protected the northern flank of Roman soldiers traveling to Britain from what is now France from Germanic tribes. “It was an early warning system to the troops in France,” Bosman explained. “It didn’t matter what the Germanic tribes put in the field as there was a legion there.” The fort was eventually abandoned in A.D. 47 when Claudius ordered all Roman troops to retreat behind the Rhine River. To read about Roman coins recovered near the ancient town of Berlicum, go to "Around the World: The Netherlands."