IOTL, Charles was persuaded by his ministers to sign a will making Philip of Anjou the heir to the Spanish crown, conflicting with the existing claim of Archduke Charles of Austria and kicking off the War of the Spanish Succession. What if he, in a fit of insanity, had instead signed the throne over to James Francis Edward Stuart, the son of the deposed King James II of England, known as the "Old Pretender"? England will obviously be...displeased, but what might the other effects be?