Both attacking and defending armies had archers, though those shooting arrows from the castle had a great advantage. First, castle archers were almost always launching arrows from a higher position than castle attackers, which extended their range and provided them with a good view of their human targets.
The castle wall also protected them well. Loopholes, the narrow slits that archers shot through, were often splayed to the inside, allowing castle archers a wide latitude of targets. The design enabled archers to hide off to the side of the loopholes while reloading, giving them protection from the rare arrow that did find its way in. Horizontally cut loopholes gave castle archers an even greater range.
The archer had three weapons to choose from. The most powerful was the crossbow. Barbs on the head of a bolt, the stout arrow shot from a crossbow, were often coated with beeswax to help them pierce armor. Crossbows took longer to load than the simple bow or the longbow. A longbow archer could shoot about 12 arrows in the time it took to launch a single bolt. Moreover, the longbow could send arrows as far as 1,000 feet. But longbows took tremendous strength to shoot and much practice to control.