The Queen braved wet British summertime weather to pay tribute to First World War volunteers on the 100th anniversary of the assassination which helped spark the conflict.
She was joined by the Duke of Edinburgh, the Earl of Wessex, Prince Michael of Kent and Princess Alexandra at the Royal Hospital Chelsea in London for a Drumhead Service of Remembrance led by the Bishop of London.
Wearing a Stewart Parvin lilac double crepe wool coat with a funnel collar, Stewart Parvin floral print dress and hat by Rachel Trevor-Morgan with flowers in it to match, the Queen sat on a covered dais as the the Last Post and national anthem were played.
Later she was taken out of the rain and into the hospital's chapel to be presented with a book listing volunteer military reservists and supporting auxiliaries from Greater London from 1908 to 2014.
Emma Bass, a civil servant who worked on the book, called Stepping Forward, shared a laugh about the weather with the Queen.
The 24-year-old, from Fulham in west London, said: "She was really friendly and said she liked our hats.
"Her hands were wet from the rain and she said it was a bit of a shame, but she really liked the book and we spoke about it being a continuous process to find out more information."
"She was really lovely, kind and amazing."
The ceremony, held on the centenary of the shooting of Austrian Archduke Franz Ferdinand in Sarajevo on June 28, 1914, featured a march by reservists accompanied by the Honourable Artillery Company band.
The Archduke's killing at the hands of Yugoslav nationalist Gavrilo Princip is widely perceived as having set in motion the chain of events that led to the First World war.
Lieutenant Governor of the Royal Hospital Chelsea Major General Peter Currie said it was "honoured and delighted" to have hosted the service.
"There is no more fitting site for this event in London than the home of the Chelsea Pensioners which for over 300 years has stood as a symbol of the nation's gratitude," he said.