to serve Mary at her own cost, but was not permitted. The Imperial Ambassador, Eustace Chapuys, suggested two years later that Mary be handed over to Margaret, but Henry refused, calling her "a fool, of no experience". Fall In 1531, Reginald Pole warned of the dangers of the Boleyn marriage. He returned to Padua in 1532 and received a last English benefice in December of that same year. Chapuys suggested to Emperor Charles V that Reginald marry Mary and combine their dynastic claims. Chapuys also communicated with Reginald through his brother, Geoffrey. Reginald replied to books Henry sent him with his own pamphlet, pro ecclesiasticae unitatis defensione, or de unitate, which denied Henry's position on the marriage of a brother's wife and denied royal supremacy. Reginald also urged the princes of Europe to depose Henry immediately. Henry wrote to Margaret, who in turn wrote to her son, reproving him for his "folly". In May 1536, Reginald finally and definitively broke with the king. After Henry's second wife, Anne Boleyn, was arrested, and eventually executed, Margaret was permitted to return to Court, albeit briefly. In 1537, Reginald (still not ordained) was made a Cardinal. Pope Paul III put him in charge of organising assistance for the Pilgrimage of Grace (and related movements). The pilgrimage was an effort to organize a march on London to install a conservative Catholic government instead of Henry's increasingly Protestant-leaning one. Neither Francis I of France nor the Emperor supported this effort and the English government tried to have Reginald assassinated. In 1539, Reginald was sent to the Emperor to organize an embargo against England—the sort of countermeasure he had himself warned Henry was possible. As part of the investigations into the so-called Exeter Conspiracy, Geoffrey Pole was arrested in August 1538. Gregory had been corresponding with Reginald; the investigation of Henry Courtenay, Marquess of Exeter (Henry VIII's first cousin and Geoffrey's second cousin), had turned up his name. Geoffrey appealed to Thomas Cromwell, who had him arrested and interrogated. Under interrogation, Geoffrey said that his eldest brother, Lord Montagu, and the Marquess had been parties to his correspondence with Reginald. Montagu, Exeter, and Margaret were arrested in November 1538. In January 1539 Geoffrey was pardoned, but Margaret's son, Henry, Baron Montagu (and cousin Exeter), were later executed for treason after trial. In May 1539 Henry, Margaret, Exeter and others were attainted, as Margaret's father had been.