Final answer:
Cardinal Wolsey was an influential figure in King Henry VIII's court, notably as his chief minister and Lord Chancellor. His most significant failure, the inability to obtain Henry's marriage annulment from Catherine of Aragon, precipitated his downfall and the English Reformation.
Step-by-step explanation:
Cardinal Thomas Wolsey served as the chief minister to King Henry VIII and played a pivotal role in the English government during the first half of the 16th century. As Lord Chancellor, Wolsey was the king's most trusted advisor, and his influence extended to all areas of policy, both domestically and abroad. He was instrumental in organizing the French campaign of 1513 and the subsequent peace negotiations, and he adeptly managed Henry VIII's court, even garnering the pope's appointment as a cardinal.
Wolsey's biggest failure was his inability to secure an annulment of Henry VIII's marriage to Catherine of Aragon, which ultimately led to his downfall and arrest. His repeated failure in this matter, combined with his accumulation of enemies and the king's disillusionment with him, resulted in his loss of power and charge of high treason. This quest for the annulment was the catalyst for the eventual English Reformation.