What happened 1921 AD in United Kingdom

In June, Churchill's mother died, followed in August by his daughter Marigold.

On 10 July 1921, the IRA ambushed British forces in Raglan street in Belfast.

Shortly after Philip's birth, his maternal grandfather Prince Louis of Battenberg, then known as Louis Mountbatten, Marquess of Milford Haven, died in London. Louis was a naturalized British subject who, after a career in the Royal Navy, had renounced his German titles and adopted the surname Mountbatten—an Anglicised version of Battenberg—during the First World War, owing to anti-German sentiment in Britain. After visiting London for his grandfather's memorial service, Philip and his mother returned to Greece, where Prince Andrew had remained to command a Greek Army division embroiled in the Greco-Turkish War.

The Peace talks led to the negotiation of the Anglo-Irish Treaty (6 December 1921).