Queen honours World War One volunteers

The Queen has attended a service to honour volunteers who served in World War One, on the 100th anniversary of events that led to the outbreak of war.

The monarch, accompanied by the Duke of Edinburgh, attended a Solemn Drumhead Service of Remembrance at the Royal Hospital Chelsea in London.

The event took place on the centenary of the shooting of Archduke Franz Ferdinand in Sarajevo on 28 June 1914.

The assassination sparked the chain of events that led to war.

It comes as Armed Forces Day celebrations take place across the country.

The Chelsea ceremony included a marching contingent of modern-day reservists from HMS President, among others, led by the Honourable Artillery Company band.

'Fitting site'

Several other members of the Royal Family, including the Earl of Wessex, Prince Michael of Kent and Princess Alexandra, also attended.

After the service, the Queen was presented with Stepping Forward, a book written in tribute to volunteer military reservists and supporting auxiliaries from Greater London 1908-2014.

The Queen was joined by the Duke of Edinburgh for the service

The Queen was presented with a book documenting the history of volunteer military reservists from Greater London

Prince Edward also attended the Chelsea service

The Royal Hospital Chelsea is home to 300 pensioners who fought in the major conflicts of the last century

Lieutenant Governor of the Royal Hospital Chelsea, Maj Gen Peter Currie said: "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."

Countdown to WW1

• 1914 Live: the day that changed the world

• How did an assassination in Sarajevo lead to war?

The World War One Centenary

Meanwhile, Bosnia is commemorating 100 years since the assassination of Austrian Archduke Ferdinand in Sarajevo, with a programme of cultural and sporting events.

Gavrilo Princip shot dead the heir to the Austro-Hungarian throne and his wife Sophie in the Bosnian capital in 1914, sparking four years of conflict.

Austria responded angrily and declared war on Serbia, securing support from Germany. Shortly after, Russia announced the mobilisation of its troops, with Germany declaring war on the country days later.

On 4 August 1914, Britain declared war on Germany.