The Duke of Cambridge Prince William recently concluded a three-week attachment to MI5, MI6, and GCHQ, the Kensington Palace wrote on Instagram.

The attachment comes as the three security services continue their vital work both at home and abroad to keep our people and our allies safe.

The Duke of Cambridge said: “Spending time inside our security and intelligence agencies, understanding more about the vital contribution they make to our national security, was a truly humbling experience.

These agencies are full of people from everyday backgrounds doing the most extraordinary work to keep us safe. They work in secret, often not even able to tell their family and friends about the work they do or the stresses they face.

They are driven by an unrivalled patriotism and dedication to upholding the values of this country. We all owe them deep gratitude for the difficult and dangerous work they do.” The Duke’s assignment began with a week at the Secret Intelligence Service – MI6 – who work secretly overseas, developing foreign contacts and gathering intelligence that helps to make the UK safer and more prosperous. They help the UK identify and exploit opportunities as well as navigate risks to its national security, military effectiveness and economy.

His second week was spent at the Security Service – MI5 – where he saw their work to protect our national security, particularly against threats from terrorism.

He finished his assignment at the Government Communications Headquarters in Cheltenham, where he spent time with those using cutting-edge technology, technical ingenuity and wide-ranging partnerships to identify, analyse and disrupt threats.

With the threat level for international terrorism in the UK set at SEVERE or above for the last five years, the Duke was keen to see first-hand the extraordinary work that staff across the Security and Intelligence Agencies do — visit GCHQ to find out more about the work of Government Communications Headquarters in Cheltenham.