Best non-fiction historical book

Another book I enjoyed is The Mystery of King John's Treasure by Shirley Charters. It's a day by day account of King John's journey across The Wash and what could have happened to the treasure.

**In the Garden of Beasts by Erik Larsen - the blurb says
“Berlin, 1933. William E. Dodd is a mild-mannered academic from Chicago who becomes America's first ambassador to Hitler's Germany. This book tells the true stroy of love, intrigue and emerging terror at the American embassy in Berlin during the tumultuous 12 months that witnessed Hitler's rise to power.”

I loved this book and often think about it years after reading it.

My favourites are
Elizabeth the Queen by Alison Weir love love love this book, have read it about 10 times.
A Time Traveller's Guide to Medieval England by Ian Mortimer, basically written like a travel guide explains where to stay, what to eat, work, leisure. There's even a section on jokes. So rich with detail.
Wild Swans by Jung Chang (the story of her grandmother who had bound feet, mother who was in the communist party and herself who was seriously into the cult of Mao).
This is going to Hurt by Adam Kay, junior doctor memoir.
Winter King by Thomas Penn ( biography of Henry VI).
Also included a couple of autobiographies- I am very selective with them as the writer has to have either a great writing style or a fascinating life but preferably both!
American Prince by Tony Curtis, warts and all surprisingly honest autobiography.
Lastly David Niven autobiographies Bring on the Empty Horses and The Moon's a Balloon. I love his warm, chatty style of writing, it's almost like you are sat at the bar while he regales you with tales of Hollywood's golden age.

I really enjoyed The Moneymaker and The Arcanum by Janet Gleeson. About the founder of paper money and the invention of porcelain.

Not historical but another winner for me was Fermat's Last Theorum by Simon Singh (OK, perhaps historical maths).

Those who liked the Mitford Girls - try The Viceroy's Daughters by Anne de Courcy.

Same type of era and brushing shoulders with the same people. These are the three daughters of Lord Curzon and I ended up pitying their lives, really. But very interesting.

Ooh I was going to recommend the Mitford Girls by Mary S Lovell but @weebarra has beaten me to it. It's more modern history but their lives were extraordinary.

I thought The Five by Hallie Rubenhold was really good.
Also, the Mitford Girls by Mary S Lovell and The Victorians by AN Wilson.

Killers of the King by Charles Spencer.
Its a study of the lives of the men who condemned Charles I after the trial. It didn''t end well for most of them.

Gentleman's Blood: A history of Dueling

This was really interesting, lots of examples of famous historical figures who fought in duels and the etiquette around it.

It's not a dense dry book either, there's a good sense of humour that I enjoyed for a subject that is quite grim when you think about it.

Just thought of another. The Age of Wonder by Richard Holmes. Another great book, about the men (and a few women) who made the scientific discoveries that revolutionised the late 18th and early 19th centuries. It's another fantastically readable book - and Holmes was so fascinated by the stories he found about one group of pioneers, the early balloonists, that he went on to write a book just about them, Falling Upwards (which I also heartily recommend).

The scientists and thinkers Holmes explores means there's a bit of crossover here with the excellent Lunar Men by Jenny Uglow, which a PP has recommended. As MadMad says, it can be exhilarating to get into a book and find it opens the doors to a whole chain of others.

Agree with @Terpsichore that Barrow's Boys is superb.

I tend to get interested in something via something else and immerse myself in it. So after Barrow's Boys I read an awful lot of exploration books - things about Scott and Shackleton, and then onto George Mallory and Everest expeditions.

The Lighthouse Stevensons by Bella Bathurst is interesting too. All about Robert Louis Stevenson's ancestors (4 generations of them, I think) who built all of the lighthouses around Scotland. Incredible feats of engineering.

Also recommend The Roses of No Man's Land if you like WW1 - lots of excerpts from women who nursed on the Western Front, etc.

I'm going to recommend Barrow's Boys by Fergus Fleming. It's an absolutely cracking book about British exploration in the 19th century, mostly at the instigation of John Barrow, who was Second Secretary to the Admiralty.

The stories of some of the exploits are just incredible (sheer foolhardiness didn't stop most of the officers who set out to try and explore Africa or sail to the Arctic - if anything, it was a plus) and tragedy isn't far behind, but the sheer ambition of the endeavours is staggering.

The most fascinating part of the book is around the Franklin expedition and its tragic and mysterious end - although there have been recent developments explaining more of what happened, that shouldn't put you off reading this book. I read Michael Palin's Erebus after this and tbh I vastly prefer Barrow's Boys.

Bess of Hardwick by Mary S Lovell is fantastic, really interesting biography of the second richest woman in Tudor England. She was a fascinating dynamic character.

Alison Weir's Lancaster and York is excellent. It gets a bit confusing in places with some of the peripheral dukes and heirs but well worth a read if the Wars of the Roses is something you fancy getting to grips with.

Bury my Heart at Wounded Knee, Dee Brown is hands down one of the best books I have ever read non- fiction or otherwise. it's a native American history of the American West and profoundly moving.

Travellers in nazi Germany by Julia boyd about the experiences of people who travelled there before the war and how gullible some of them were but not all.
Heavens Command by Jan Morris about the British empire - not turgid or dry but really brings to life the experiences of ordinary people.
Bill Bryson - At home, A short history of Everything and Summer 1927 mass market but still good.

Ungrateful Daughters by Maureen Waller. About Mary and Anne, the daughters of James the Second. Very readable about an era not very well covered.

Empress Dowager Cixi: The Concubine Who Launched Modern China by Jung Chang

Persian Fire by Tom Holland

The Rasputin File by Edvard Radzinsky was very interesting.

Blood River by Tim Butcher, which is kind of travel, history and current affairs all mixed together. It's about the Congo River.

The Five - Helen Rubenhold. It's the biographies of five victims of Jack the Ripper. Utterly fascinating and an incredible insight into how hard the life of the poor was in Victorian Britain - and how quickly life could spiral out of control.

Chocolate Wars by Deborah Cadbury is really interesting and well written.
Not exactly what you asked for, but brilliant is Travels in to the Interior of Africa by Mungo Park.

The Invisible Woman: The Story of Nelly Ternan and Charles Dickens by Claire Tomalin,

Mrs Jordan's Profession by Claire Tomalin,

Locust: the Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier by Jeffrey Lockwood,

The Ghost Disease and Twelve Other Stories of Detective Work in the Medical Field by Michael Howell and Peter Ford,

The Immortal Life of Henrietta Lacks by Rebecca Skloot.

Erebus: The Story of a Ship by Michael Palin - about the Franklin expedition.

A Distant Mirror by Barbara Tuchman (all of hers are wonderful)

The biography of Peter the Great by Robert Massie is great. I liked most of Antonia Frazers biographies too.

Judith Flanders' books about the 19th century: Consuming Passions: Leisure and Pleasure in Victorian Britain, The Victorian City and The Victorian House: www.judithflanders.co.uk/books/