The Queen attended a number of engagements before spending a night in hospital on Wednesday.
She was ordered to rest by doctors and advised to miss a trip to Northern Ireland following her busy schedule.
Here is what the 95-year-old monarch has been up to since her return to Windsor Castle at the start of October:
She meets Canadian troops from 1st Regiment Royal Canadian Horse Artillery, and later has a telephone audience with Prime Minister Boris Johnson.
– October 7: The Queen, with the Earl of Wessex, launches the Queen’s Baton Relay for the Birmingham 2022 Commonwealth Games from the forecourt of Buckingham Palace.
– October 12: The Queen, accompanied by the Princess Royal, attends a Westminster Abbey service of thanksgiving to mark the centenary of the Royal British Legion.
She uses a walking stick at the abbey – the first time she has done so at a major event.
– October 13: The monarch has a face-to-face audience with pianist Dame Imogen Cooper to present her with the Queen’s Medal for Music. She also holds three other audiences.
– October 14: On an away day to Cardiff, the Queen delivers a speech at the sixth session of the Welsh Senedd.
– October 16: The Queen enjoys a day at the races at Ascot, and presents the trophy after the Queen Elizabeth II Stakes during the Qipco British Champions Day.
– October 18: She holds a virtual audience with the new Governor-General of New Zealand, Dame Cindy Kiro.
– October 19: The Queen has three engagements – two virtual audiences with the Japanese ambassador and the EU ambassador, and then hosts an evening reception at Windsor Castle to mark the Global Investment Summit.
