Speech by Mr Andrew Bailey, Governor of the Bank of England, at the unveil of the Alan Turing £50 polymer banknote, London.

It's my great pleasure to unveil the new £50 note, which will feature one of Britain's most important scientists, Alan Turing. Turing is perhaps best known for his codebreaking work during World War II, which played a decisive role in bringing that conflict to an end. But he is also recognised as being a pioneer in computing and artificial intelligence, and someone whose work has had an enormous impact on how we all live today.

The process of selecting Turing started when we asked the UK public to "Think Science" and put forward nominations for scientists they would like to see appear on a banknote. We had an overwhelming response, with nearly 250,000 members of the public making a nomination. I'm glad that so many of you wanted to be a part of this process. There's something of the character of a nation in its money, and we are right to consider and celebrate the people on our banknotes.

Above and below the micro-chip image are green metallic sunflower shapes, and on the back of the note, a red foil patch containing the letters "AT" is based on the image of a sunflower head. These sunflower images reflect Turing's ground breaking morphogenetic work. This new branch of developmental biology which Turing pioneered, was the study of algorithms underpinning the formation of patterns in nature. The way a leopard's spots develop into patterns, or the way the seed heads on a sunflower spiral. Turing found a way to predict these using maths. Here, also, we see him laying the foundations for a new scientific field.

His contributions to Britain's war effort and its scientific status, make the circumstances of his own death all the more poignant. Though guarded about his private life, Turing's sexual orientation wasn't a complete secret at the time. He was arrested under indecency laws in 1952, after the police learned of his relationship with another man. The tragic events surrounding this arrest would eventually lead to Turing taking his own life, at the age of just 41.

In 2017 the Turing Law was passed in memory of Alan, pardoning all men who, like him, were convicted based on their sexuality. Another legacy for which Alan Turing can be remembered.

The Turing £50 completes our family of polymer banknotes, which already include the £5, £10, and £20 pound notes. These polymer notes are more secure than their paper predecessor, and I'm very pleased that we have made this important transition.

Conclusion

Winston Churchill, Jane Austen, JMW Turner.

These are the figureheads who grace our other banknotes, and through their leadership and cultural contribution, they helped shape the vibrant society that is modern Britain.

The person chosen to feature on a currency, can embody the spirit of a nation. In his remarkable achievements, Turing did just that. And in doing so, showed us the way to the future.

As the artist Anthony Gormley remarked, Alan Turing "unlocked the door between the industrial and the information age". And although Turing was under appreciated in his lifetime, we can now see how accurate this description is.

Alan Turing was a gay man, whose transformational work in the fields of computer science, codebreaking, and developmental biology, was still not enough to spare him the appalling treatment to which he was subjected. By placing him on this new £50 banknote, we celebrate him for his achievements, and the values he symbolises, for which we can all be very proud.