Celebrations marking the 800th anniversary of the Magna Carta have been launched by the Duke of Cambridge with the unveiling of artwork symbolising one of the document's most important clauses.
On the site at Runnymede where King John accepted the historic document that limited the power of the Crown, William was given a first glimpse of the installation piece called The Jurors by artist Hew Locke.
Twelve bronze chairs are arranged facing each other, inspired by the 39th clause of Magna Carta, which gives the right to a jury trial.
The unveiling was the beginning of an international celebration of the Magna Carta which will be attended by the Queen, Duke of Edinburgh, Prime Minister, Archbishop of Canterbury and thousands of guests.
Each chair is decorated with images and symbols relating to past and continuing struggles for freedom, rule of law and equal rights.
It even includes a loudhailer belonging to Harvey Milk, the gay rights campaigner and the first openly gay person to be elected to public office in California.
Before the Duke arrived, Mr Locke said: "It's a very complex piece of work. If you look at it, you will see certain things in it. The piece is something that reveals itself in layers.
"The Magna Carta is a precious document and commemorating it with a bronze piece - that's a precious thing. This is a piece for people, this is for regular people."
The artist said the artwork, which will remain at the site where the Magna Carta was sealed, was completed when members of the public sat down in the chairs - and when William arrived he took a seat, joining performance artists already seated.
David Cameron is due to give a speech and will say that fundamental reforms to UK human rights laws are required to "safeguard the legacy" of Magna Carta.
The Prime Minister will say its principle is "as relevant today as it was then" and remains "sewn into the fabric of our nation, so deep we barely even question it" but will complain that the notion of human rights in Britain eight centuries on has been "distorted and devalued".