To state the obvious, it’s not exactly a regular occurrence for a member of the Royal Family to give evidence in a court of law.
But with his statement to a French court today, Prince William has let it be known he will do whatever it takes to protect the privacy of his wife and family.
The Duke of Cambridge told the court the publication of topless picture of his wife was “particularly shocking” given his mother’s battles with the paparazzi before her death in Paris in 1997.
William and his brother Harry will mark the 20th anniversary of their mother’s death this August.
Six people are on trial in France over the publication of the photos of the Duchess of Cambridge in 2012.
They are being prosecuted under France’s strict law on privacy.
The photographs were taken while the couple spent a private holiday at a chateau in Provence owned by the Duke’s relative Viscount Linley.
Viscount Linley, now Earl of Snowden, is the son of the Queen’s sister Margaret.
Prince William told the court: “The clandestine way in which these photographs were taken was particularly shocking to us as it breached our privacy.”
The French glossy magazine Closer printed the pictures, as did a regional paper, La Provence.
The editor of Closer, the boss of its publishing group are both facing privacy charges as is a director of the regional newspaper.
Three photographers face charges of invasion of privacy and complicity.
They deny taking the pictures.
A lawyer representing Closer magazine told the court the Duke and Duchess were seeking compensation of £1.3 million.
In France, the laws on privacy are much stricter and the country’s constitution demands that everyone has the right to privacy.
But the punishment for the offence might not be very severe and may only run into tens of thousands of Euros.
The Duke’s statement, read in French to the court, also said: “The facts in this case are particularly painful as they remind us of the harassment which caused the death of my mother, Diana Princess of Wales.”
At the time the pictures appeared in a number of other European titles – but never in the UK.
A verdict is expected in July.