Kate first visited Bletchley Park in 2014 to explore a family connection; her paternal grandmother Valerie Glassborow worked as a "Duty Officer" at Bletchley with her twin sister Mary during the war. As with so many people who worked in British Signals Intelligence, very little is known about their work. Valerie's records were among many destroyed after the war.
Valerie married RAF pilot Peter Middleton in 1946 in Leeds and they had four children including Kate's father Michael Middleton. Valerie died aged 82 in 2006 and her husband Peter died on 2 November, 2010 aged 90. William and Kate's engagement announcement was delayed because of his death. Kate was very close to both of them.
During the 2014 visit Kate remarked: "It's so moving for me, and to be here as well. I was aware of it when I was a young girl and I often asked granny about it but she was very quiet and never said anything."
For a 2016 puzzle book produced by GCHQ, the UK’s Signals Intelligence and Cyber Security agency, the Duchess wrote: "I have always been immensely proud of my grandmother, Valerie Glassborow, who worked at Bletchley Park during the Second World War. They hardly ever talked about their wartime service, but we now know just how important the men and women of Bletchley Park were, as they tackled some of the hardest problems facing the country".
Today, Kate was delighted to learn the names of her grandmother and great-aunt are the latest additions to Bletchley's Codebreakers' wall.
More from the Mail Online:
'The Duchess of Cambridge spoke of how her code-breaker grandmother felt unable to tell her about the vital work she did at Bletchley Park before she died, as she told other veterans: ‘You were so very important.’
Kate, 37, who was shown a new memorial of bricks containing the name of her grandmother and great-aunt when she visited the legendary Second World War headquarters today, said her said her granny - like so many others - had been ‘so sworn to secrecy that she never felt able to tell us’ about what she did.'
In August 1938, the arrival of 'Captain Ridley's Shooting Party' at Mansion House in the Buckinghamshire countryside was to set the scene of one of the most remarkable stories from World War II. They appeared to be a group of friends enjoying the end of summer, even bringing a chef from the Savoy Hotel with them. But appearances were deceptive, the small group comprised of members of MI6 and the Government Code and Cypher School turned codebreakers. Their job - to see whether Bletchley Park would work as a wartime location.
More from Bletchley: "The mission was to crack Nazi codes and ciphers. The most famous of the cipher systems to be broken at Bletchley Park was the Enigma. There were also a large number of lower-level German systems to break as well as those of Hitler's allies."
In early 1939 the codebreakers returned to Bletchley Park to begin their war-winning work.
The Mansion today.
It includes an immersive film, based on newly declassified material, which shows how the intelligence effort coordinated at Bletchley Park helped specifically in the success of the D-Day landings at Normandy. Using sophisticated codebreaking techniques, workers at Bletchley Park fed crucial information to Allied forces in the critical months, weeks and days leading up to D-Day on 6th June 1944.
Kate viewed the interactive exhibition and met those involved in the restoration of the building.
The Duchess then joined a group of schoolchildren involved in a workshop based on the new exhibition, which allows pupils to take on the role of codebreakers, intercepting and deciphering German communications in order to understand their order of battle and decide whether the Operation Fortitude deception plans have been successful.
Kate and the students used a real Enigma machine.
The pre-show display.
A trailer from the exhibition.
Coincidentally, I enjoyed listening to Jonathan Freedland's broadcast from Bletchley for Radio 4's The Long View. The episode titled 'Women in intelligence and cybersecurity' compares efforts to recruit more women into intelligence and cybersecurity today to the recruitment of women at Bletchley Park during the War. It was fascinating to hear about the recruitment process; for example bilingual candidates or those with musical qualifications were highly sought after. By the end of the war, 75% of the codebreaking workforce were female - not just a groundbreaking statistic then, but by today's standards. Freedland speaks to Charlotte Webb, who worked at Bletchley. For those interested in learning more, Webb wrote an incredibly insightful book, Secret Postings: Bletchley Park to the Pentagon. To listen to the broadcast please click here (apologies if it is not available in your region).
The Duchess received a gorgeous posy from a very excited boy named Lawson before leaving.
Rebecca English reports Kate shared a little update on Louis:
'Mrs Rose offered her ‘congratulations on your beautiful family’, to which Kate revealed that little Louis, one, was already running amok. ‘Thank you so much. Louis is keeping us on our toes,’ she said. ‘I turned around the other day and he was at the top of the slide - I had no idea!’
Given four cuddly toys by the primary school codebreakers: a squirrel, fox, owl and rabbit for George, Charlotte, Louis and baby Archie, she said: ‘They love wild animals. They will look after these.’
A video from the visit.
Kate wore her Alessandra Rich Pleated polka-dot silk crepe de chine midi dress for the engagement.
The £1,225 piece is described: "Alessandra Rich was inspired by Alfred Eisenstaedt's 1945 photograph of a sailor kissing a stranger in Times Square for her Spring '18 collection. Capturing the essence of that iconic moment, this vintage-inspired dress is cut from polka-dot silk crepe de chine that falls to a pleated midi skirt."
Readers will recall, Kate wore the dress for Prince Charles' 70th birthday portraits.
Kate carried her Smythson Panama purse.
The Duchess wore her Emmy London Rebecca pumps in 'Riviera'.
And accessorised with her Annoushka pearls.
Very fittingly, Kate wore her grandmother Valerie's brooch.
In other news, William and Kate are travelling to Windsor later today to meet Baby Archie. I expect they'll take George, Charlotte and Louis when they return home from their engagements.
With just one week to go until the 2019 RHS Chelsea Flower show officially opens to the public, Kensington Palace released three new image of the Duchess making preparations for her 'Back to Nature' garden.
Kate joined landscape architects Davies White and together, they visited nurseries, suppliers and craftspeople who have been building elements of the garden. The garden will highlight the importance of embracing nature for physical and mental health.
We'll almost certainly see the Duchess, and other members of the royal family accompany the Queen, on Monday 20 May, for the preview day. I'm very excited to see Kate's completed garden. Several elements of the garden mirror aspects of the outdoors, which the Cambridge children love. Wouldn't it be fun if George, Charlotte and Louis joined their parents?
And to mark Mental Health Awareness Week, Prince William joined Stephen Fry, Katy Perry, Alesha Dixon and Jameela Jamil to record a special one minute message encouraging listeners to take a minute, and really listen. The message was broadcast across 300 radio stations. Mental Health Minute comes days after the launch of Shout, a new 24/7 text messaging line for people in crisis. To find out more please click here.
Finally, it's officially Garden Party season! This year's Buckingham Palace parties take place tomorrow, the 21st and 29th. We can expect to see the Cambridges at one of them. A couple of readers have commented about the possibility of the young royals attending Lady Gabriella Windsor's wedding on Saturday. Simon Perry reports there will be a strong turnout from the family, but "William, Kate, Harry and Meghan won't be there".