This is a review for the complete first series that takes place on Anyar and follows the destiny of Yozef Kolsko (formerly known on Earth as Joseph Colsco) from his (litetally) naked arrival there (and the events leading to it which are in the usual vein, aliens under stealth observing Earth, accident caused by them leading to the destruction of a plane, a dying Colsco is saved and "rebuilt" but cannot be returned to Earth etc) to the end of the storyline on Anyar in which he becomes a major character.
The series has 4 volumes - Cast Under an Alien Sun, The Pen and the Sword, Heavier than a Mountain and Forged in Fire and they form a complete (very) long novel with a definite ending though of course, the story continues in more books.
The books generally start with a fast recap of what came before and a little more detail about that than in the previous volume, and they have a fairly large cast, though the action generally is presented from Yozef's perspective and from the perspective of the main antagonist, the Narthani general and colony governor Okan Akuyum, though there are many other pov's, not least, the one of Maera Keelan, the super-smart elder daughter of Caedellium clan leader Cullich (Keelan), who is the main (unofficial - as the society is fairly patriarchal, though not exclusively with many women in important roles) advisor of her father and from whose sons (once she is married of course) the new clan hetman is to be chosen (as Culich has 4 daughters), but the problem is that once she threw out a few potential suitors as dumb and conceited, nobody is brave enough to court her, while the younger daughters usually cannot marry first by tradition, so she needs an unusual husband...
Caedellium is an island the size of a large European country and divided into 21 clans which are fiercely independent, though due to the existence of an all-clan conclave do not generally war against each other (they actually do not have the term for war, just for battles and fights in their common language), but skirmish occasionally along the borders. The society and technology on Caedellium is about a mid-1700's one, though there are somewhat more advanced states on the continents of Anyar - there is no steam power or electricity, so all are still preindustrial with muskets, pikes and guns.
However, a few years previously, the Narthani empire - an aggressive empire descending from steppes people, who enslave and absorb anyone they can, put Caedellium in their sights as a base to attack some of their main enemies - pretty much all the other major countries of Anyar on a few but close landmasses (all are in one hemisphere, though the humans of Anyar have sailing ships capable of circumnavigating the globe, with the other hemisphere being all ocean), are now semi-allied against the Narthani who dominate the main landmass and are very brutal but have been checked by various alliances on each land border, so now look at invading the other smaller continents. Using the usual "pretend to come to trade" tactic, the Narthani were welcomed into the main island port of Preddi, capital of the clan with the same name, slowly expanding their presence there and fomenting attacks from the Preddi' stupid clan neighbors, the Eywell and Selfcell, which leade to the Preddi requesting Narthani help for defense, the Preddi being conquered and either enslaved or kept as workforce, while tens of thousands of Narthani civilian colonists were shipped in to populate the towns and farms of the Preddi, while the Eyewell and Selfcell saw the writing on the wall and accepted Narthani as overlords, with the Selfcell hetman appealing in vain for help to the all-clan alliance. And now, the Narthani are ready to start the full conquest, though they still have to proceed slowly since the conquest has been planned to be done "on the cheap", so slow and careful with relatively few soldiers and the goal of exploting the divisions of the clans...
But Yozef (as the natives pronounce his name) doesn't know anything when he washed out naked out of the sea on the fringes of the Keelan province in the village of Abersford and is taken in by Sistian and Diesa Beynom, Abbott and Abbess of St Sidryn's abbey, who nurse him to health, tutor him in the language and later help him integrate in the Abersford society and put his ideas in practice (on Earth, Joseph was a Chemistry PhD student who invented, with an upcoming patent and lucrative job offers) starting with ether for surgeries, to soaps, hard liquor and slowly much, much more.
As Yozef finally comes to term with his new life and becomes quite content and ready to live as a dutiful Caedellium man, expand his businesses, the Narthani start their next phase of invasions with pirate attacks (led by paid mercenary pirates from across the sea for deniability) and to no reader's surprise one of the targets is St Sydrin and Abersford in general... And so it goes for 4 not to be put down volumes until the conclusion of the storyline; much will happen of course but I recommend to read the books and find out what.
The style is straightforward, but the books general read fast and easy, no clunky prose and overmuch info-dumps (there are some by necessity, but they get fewer as the series advances); the characters are very intriguing and the storyline which alternates between action and the life of Yozef 9obviously they will converge eventually) is extraordinarily captivating.
Highly, highly recommended - one of the best series I've read in recent times