A muster meant that men in the local shires were called together to identify those able to serve in the King's army. The muster records thereby created represent a valuable source of information about the local military resources and also gives the names of those involved. The documents which form the subject of this edition, the Herefordshire muster books for 1539 and 1542, came into existence during two military and diplomatic crises. Neither lasted long. The first was during Thomas Cromwell's term of office, the second after his fall. The first crisis was precipitated by the rapprochement between France and the Emperor Charles V signalled by the Treaty of Toledo on 12 January 1539; these powers then withdrew their ambassadors from London and made demonstrations of apparent warlike intent. Henry VIII's Council, then dominated by Thomas Cromwell, called for musters throughout the country. The commissions of array represent an attempt to discover the country's military resources