The Queen has carried out her first official engagement since she had surgery on her knee 16 days ago.

She formally unveiled a set of wrought iron gates on her Sandringham estate in Norfolk on Wednesday.

The gates were presented by the armed forces to mark her Golden Jubilee.

The 76-year-old monarch used a walking stick as she examined the gates with the Duke of Edinburgh and senior army, navy and air force officers.

The Queen leaving the hospital

The Queen hurt her right knee during a private visit to Newmarket racecourse in Suffolk before Christmas.

She had surgery to remove a piece of torn cartilage at the King Edward the Seventh Hospital in London.

After an overnight stay the Queen returned to Norfolk to recuperate.

As a result of the surgery the Queen has cancelled a number of engagements.

She was due to visit Chelmsford Cathedral in Essex on Friday to attend a service to mark the anniversary of the 1953 floods.

But the Earl and Countess of Wessex will now attend instead.