By 1572 Gilbert had turned his attention to the Spanish Netherlands, where he fought an unsuccessful campaign in support of the Dutch Sea beggars at the head of a force of 1,500 men, many of whom had deserted from Smith's aborted plantation in the Ards of Ulster. In the period 1572–1578 Gilbert settled down and devoted himself to writing. In 1573 he presented the Queen with a proposal for an academy in London, which was eventually put into effect by Sir Thomas Gresham with the establishment of Gresham College. Gilbert also helped to set up the Society of the New Art with William Cecil, 1st Baron Burghley and Robert Dudley, Earl of Leicester, both of whom maintained an alchemical laboratory in Limehouse.