Britain’s Queen Elizabeth II is recovering at Windsor Castle after coming down with a stomach bug that forced the cancellation of a royal engagement.

The 86-year-old monarch had been due to visit Swansea, Wales, on Saturday to present leeks a national symbol to soldiers of the Royal Welsh Regiment in honour of Wales’ national day, St. David’s Day.

The monarch, who celebrated 60 years on the throne last year, rarely misses engagements due to ill health.

She last cancelled an engagement five months ago because of a sore back.