Eleanor Cobham, Duchess of Gloucester was one of the more high profile individuals to be accused of wielding magic. In 1441, she was accused of treasonable necromancy. She had consulted with Astrologers that had foreseen the King’s death in a matter of months. The Astrologers had told the court that Eleanor was the instigator.
Eleanor fled to sanctuary in Westminster Abbey so could not be tried by the law courts. The charges against her were possibly exaggerated to curb the ambitions of her husband. Eleanor was examined by a panel of religious men whilst in sanctuary and she denied most of the charges but confessed to obtaining potions from Margery Jourdemayne, “the Witch of Eye”. Her explanation was that they were potions to help her conceive.
Eleanor and her fellow conspirators were found guilty. The Astrologers either died in the Tower of London or were hanged, drawn and quartered, and Jourdemayne was burnt at the stake. Eleanor had to do public penance in London, divorce her husband and was condemned to life imprisonment.
Sources (because I don’t know everything)
‘Eleanor, Duchess of Gloucester’ from the website ‘Wikipedia’. Accessed from https://en.wikipedia.org/wiki/Eleanor,_Duchess_of_Gloucester
‘Royal Witches, From Joan of Navarre to Elizabeth Woodville’ by Gemma Hollman. Published 2019.