So began what has been called one of the most brazen confidence tricks in history—the Poyais scheme. MacGregor devised a tricameral parliament and other convoluted constitutional arrangements for Poyais, drew up commercial and banking mechanisms, and designed distinctive uniforms for each regiment of the Poyaisian Army. His imaginary country had an honours system, landed titles, a coat of arms—doubly supported by Poyers and unicorns—and the same Green Cross flag he had used in Florida. By the end of 1821 Major William John Richardson had not only accepted MacGregor's fantasy as true but had become an active ally, providing his attractive estate at Oak Hall, Wanstead to be a British base for the supposed Poyaisian royal family. MacGregor gave Richardson the Order of the Green Cross, commissioned him into the Poyaisian "Royal Regiment of Horse Guards" and appointed him "chargé d'affaires" of the Poyaisian legation at Dowgate Hill in the City of London—the top representative of Poyais in Britain. Richardson's letter of credence from "Gregor the First, Sovereign Prince of the State of Poyais" was presented to George IV. MacGregor had Poyaisian offices set up in London, Edinburgh and Glasgow to sell impressive-looking land certificates—initially hand-written, but later printed—to the general public, and to co-ordinate prospective emigrants.