Supply, supply, supply

How did armies keep their archers supplied with arrows while fighting?

"In 1418, Henry V's government purchased 150,000 arrows; in 1421, it acquired nearly 500,000. Several years' supply would be stockpiled for a major campaign. Half a century earlier in 1360, Edward III's accounts reveal that 566,400 arrows (and 11,000 bows) were stored in the Tower of London alone."