Roman conquerors built monuments to celebrate their victories. Trajan, who ruled from AD98-117, was a famous soldier who became emperor of Rome. He led Roman armies on one of their most successful conquests, in Dacia(Romania) in AD106. To record this achievement he gave orders for a tall stone pillar(now known as Trajan's Column) to be built in the Forum in Rome. It was almost 30 metres high, and was decorated with carvings of 2,500 Roman soldiers winning wars.