 When Perkin Warbeck impersonated Edward IV's presumed-dead son Richard of Shrewsbury, 1st Duke of York, in 1499, Margaret's brother Edward was attainted and executed for involvement in the plot.Richard Pole held a variety of offices in Henry VII's government, the highest being Chamberlain for Arthur, Prince of Wales, Henry's elder son.When Arthur married Catherine of Aragon, Margaret became one of her ladies-in-waiting, but her entourage was dissolved when the teenaged Arthur died in 1502.