I recommend Umberto Eco: The Island of the Day Before.
It’s historical fiction, with a bit of a nautical bent set in the age of exploration, but it’s Umberto Eco so there is all sorts of mystical weirdness and layers of meaning built into the story as well.
Read “One Second After” and sequels.
“The Killer Angels” about the battle of Gettysburg is awesome. It is written as historical fiction but is well researched and very accurate. Best war novel ever written.
My wife gave me the Hornblower series for Christmas, and I’ll get at them soon. (I have read them all, but not for many years.) The Patrick O’Brian books are great, though it might be a bit daunting to read them all in a row.
Try some of Kenneth Roberts’s historical fiction, like “Rabble in Arms” or “Lydia Bailey”.
Try Dick Francis. In order. World of British steeplechase. As engaging as sci-fi.
I really liked the Master and Commander series.
TRINITY: The Best Kept Secret. Jacques Vallee. Paola Harris. (just published)
The Real Anthony Fauci. Robert F. Kennedy, Jr. (strange for a hard-bitten conservative like me to recommend anything from a Kennedy)
Read all of Kenneth Roberts historical fiction about the Colonial and Revolutionary era. He is a wonderful author. I would read “Arundel” first, then “Rabble in Arms.” You like naval history and you get it in spades in “Rabble in Arms” with the Battle of Valcour Island on Lake Champlain.
Seen in the perspective of history, the Battle of Valcour Island, fought on Lake Champlain between improvised navies of Britain and America in October, 1776, looms out of all proportion to the size of the forces engaged, the number of ships sunk, or the losses suffered in wounded and killed.
Not only was this savage three-day battle the first fleet action ever fought by Americans; it was also a great strategic triumph for the colonists’ brilliant and resourceful commander, Brigadier General Benedict Arnold, ultimately destined to betray the cause for which he fought so valiantly. More remarkable still, even though Valcour was an American defeat, it proved to be one of the truly decisive battles of the American Revolution.
“When Benedict Arnold on Lake Champlain, by vigorous use of small means, obtained a year’s delay for the colonists,” states the distinguished U.S. naval historian Admiral Alfred T. Mahan, “he compassed the surrender of Burgoyne in 1777.” That surrender, Mahan asserts, convinced France that she should place her mighty financial and military resources firmly behind the cause of the Americans, so ensuring their ultimate victory. (American Heritage)
Rabble in Arms was hailed by one critic as the greatest historical novel written about America upon its publication in 1933.
If you like Hornblower and Sci-Fi you might like that.
Bernard Cornwall, his Sharpe series.
Oh, and Bernard Cornwell’s Sharpe series.
Harold Coyle writes amazing military fiction.
Stirling’s “The Domination” is three books in one—a SF military classic.
The Joel Rosenberg series.
I like WWII non-fiction and my most recent reads/suggestions:
If naval warfare is your preference, the Ian Toll’s Pacific War trilogy might be for you:
Pacific Crucible
The Conquering Tide
Twilight of the Gods
In that order.
Land/tank warfare:
Spearhead by Adam Makos. Soon to be a major motion picture.
Air war:
Masters of the Air by Donald Miller. Soon to be a mini-series in the Band of Brothers/The Pacific tradition, although not HBO this time.
Robert Graves, I Claudius, and Claudius the God.
Wow, I knew I could count of my fellow Freepers for some really excellent suggestions!
—submarine warfare, mostly WW 2and current—
P.T. Deutermann—
Your decision as to whether to continue with the exploits of Jack Aubrey through all 20 volumes may benefit by a view from 30,000 feet.
https://en.wikipedia.org/wiki/Aubrey%E2%80%93Maturin_series
I’ve been enjoying a paced read through “Robinson Crusoe”; the 18th Century English adds an interesting educational element to the experience. I continually find myself discovering “Ahh, so that’s how they would have put it back then.” Modern wokesters would likely torch it over its references to “savages” of the African and American continents, but it’s very much a product of its day (1719), and not at all unapproachable for a sound-minded reader.
Candace Robb - The Owen Archer Series (13 books) ...
Lindsey Davis - The Marcus Didius Falco Series (21 books) ..
And, if you like fantasy mysteries, you might try Glen Cook, the Garrett P.I. series (14 books) ...
I know my voice will be lost among the other recommendations and there is no way for you to tell that what I am about to say is the answer you really want. I fancy I know why you like Hornblower which is why I recommend the historical fiction by Raphael Sabatini. Start with “Captain Blood” and if you don’t care for it then please message me and tell me why not. I like to keep track of when I am wrong, happens often I’m afraid, but not this time. (Ignore the silly Hollywood movies which claimed to be based on his books such as “Captain Blood” starring Erroll Flynn.)
Raphael Sabatini!
“Scaramouche”
“The Sea Hawk”
Here is a list from thriftbooks:
https://www.thriftbooks.com/a/rafael-sabatini/311837/