Changes also took place within the recruitment and composition of armies. The use of the national or feudal levy was gradually replaced by paid troops of domestic retinues or foreign mercenaries. The practice was associated with Edward III of England and the condottieri of the Italian city-states. All over Europe, Swiss soldiers were in particularly high demand. At the same time, the period also saw the emergence of the first permanent armies. It was in Valois France, under the heavy demands of the Hundred Years' War, that the armed forces gradually assumed a permanent nature.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): Which English king is associated with the use of mercenaries in the 13th century?
unanswerable