As different countries grew up in Europe, they struggled for power and fought almost constantly, so kings needed to be good at leading their soldiers in war. Weapons such as axes and swords were used in hand-to-hand combat, while bows fired arrows at enemies at a distance. Owning fine weapons was also a way of showing how rich and important you were.
Wars were a huge drain on the people of a country. They had to provide money in their taxes to pay for them, and often they were left without homes, or even with their lives in danger.