In January 1820 a military mutiny or pronunciamiento in Spain obliged King Ferdinand to accept the constitution of 1812 which he had abolished. The news had the effect of a whiplash on Alexander: more than one Tsar had been toppled and/or murdered by army mutinies. The news which arrived a couple of weeks later, that on 13 February the heir to the French throne, the duc de Berry, had been assassinated only deepened his sense of horror.
