EXCLUSIVE: The celebrated actress had absolutely no idea of the vital role her mother played in setting the allies on course for victory06:43, 20 Jul 2026Updated 06:43, 20 Jul 2026Dame Harriet Walter has told of her astonishment at the “extraordinary” discovery that her mother played a key part in the war effort - and never told her.‌Xandra Carandini Lee - the elder sister of renowned actor Sir Christopher Lee - was married to Harriet’s father Roderick Walter whose great, great grandfather was John Walter, who founded The Times in 1785. But for her Who Do You Think You Are? programme, Harriet wanted to trace her mother’s lineage which she knew involved Italian aristocracy and also ancestors in Tasmania.‌However, her first line of inquiry leads to the revelation that her mother played an important role in the success of the 1944 D-Day landings, which she learns thanks to ground-breaking research on women in wartime intelligence conducted by Dr Helen Fry.‌When the war broke out in 1939 her mother was working as a secretary but later she joined the Admiralty intelligence having been invited as a “temporary section assistant” in 1943.Dr Helen tells the actress, known for her high profile roles in TV dramas including Succession, Wolf Hall, Downton Abbey and Killing Eve, that her mother is not working as a typist or a secretary.‌Xandra had described her wartime role to her daughter as being “one of the cogs in the machine” which the actress now knows was something of an understatement. “She never talked about it,” Harriet, 75, tells the camera. “I would love to know about that side of my mother’s past because she just never thought she’d done anything very interesting - and I thought ‘I bet you did’.”She discovers that by the time “Operation Neptune” - the codename for the Normandy landings - was being planned, her mother was an intelligence officer. For the invasion of occupied France, Xandra was put in charge of “all harbour defence activities particularly between Cherbourg and Le Havre”.‌“Those are the beaches of Normandy,” Dr Helen says. “To get this in perspective, your mother was in charge of the whole intelligence picture, for naval intelligence, for the D-Day landings.”She explains: “Your mother, and those working under her, were constructing intelligence summaries and reports for commanders, Winston Churchill himself, to decide where are we going to mount these landings? She’s helping to collate the movement of German ships, of U-boats, coastal defences - anything that’s of relevance to the Admiralty. Because if you’re going to land your troops you’ve got to know what your forces are going to actually face.”‌Harriet is told that Xandra would have spent the night of the first landings analysing intercepted messages from the Germans, de-coded by Bletchley Park. “Wow, it’s just astounding,” the shocked actress declares “I had a rather frivolous idea of her just having a great time in the canteen and flirting with the boys. I had no idea she had this sort of responsibility. That is extraordinary.”Speaking after filming ended, Harriet, who does not have children and has one sister, said she had shared the exciting family news with her remaining family. “Unfortunately, my generation is the oldest now. I would love to be able to ask my mother more details about her war and express my admiration of her. My grandmother would have known a lot already, so my main question is ‘Why didn’t you tell me all this?’”She says her mother always played herself down. “She was a very sweet woman who had an amazing sense of humour but she was sort of slightly belittled by the men in my family.”‌Her new-found knowledge makes Harriet feel conflicted about how her mother was treated by others during her lifetime. “I”m sorry to say this but when I think how she was put down by my dad and my step-father - you know, ‘your mother’s not very logical’. Had they only known what she’d done, they might have treated her with more respect. I’m rethinking my mother entirely.”She is told simply that Xandra took her oath of secrecy very seriously and Harriet, who received her damehood in 2011, the same year that her mother died, says she wishes she had known earlier. “I’m astounded that my mother had any kind of significance in the war effort because she never exposed anything of that sort,” she admits. “She was the epitome of modesty - ‘oh, I don’t matter darling’.“I feel silly that I’ve got some kind of fame for having done absolutely nothing except pretend to be other people for a living. And she had quite a strong role in the D-Day landings, which opened up the whole path to peace. Good for her.”Article continues belowFor the BBC programme Harriet also travels to Tasmania to find out about her great great grandfather Girolamo being a dancer who suffered with financial problems, and his wife Maria being a famous opera singer.- Harriet’s episode of Who Do You Think You Are? airs on July 30, BBC1, 9pmLike this story? 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