On December 12, 1936, a deeply disgruntled Zhang Xueliang kidnapped Chiang Kai-shek in Xi'an, hoping to force an end to the conflict between KMT and CPC. To secure the release of Chiang, the KMT agreed to a temporary end to the Chinese Civil War .
On 12 December 1936, the disgruntled Zhang Xueliang and Yang Hucheng conspired to kidnap Chiang and force him into a truce with the CPC. The incident became known as the Xi'an Incident.
On 12 December 1936, at the accession meeting of the Privy Council of the United Kingdom, George VI announced he was to make his brother the "Duke of Windsor" with the style of Royal Highness.