story identification - Novel where the protagonist is integrated into alien society of desert dwellers

A space-faring human is paid/contracted to integrate with a desert people who are VERY in-touch with the desert - a la Avatar?

I remember the desert people were taller and thinner than humans, used Saracen-style Scimitar swords, had their own alien language, and over the course of the book (books?) integrated this man into their society.

He ultimately went native -- I remember this because he would wear their robes, bathe with sand, and shave all of his body hair.

It's a book I read in the early 90's, and I would like to read it again, but my Google-Fu has failed me. :(

EDIT: The desert people are used as bodyguard/mercenaries due to their excellent swordsmanship/fighting prowess and their very strict honor/belief system similar to Bushido. They eschew technology, but are exposed to it enough that space travel is a non-issue. The protagonist is also a space/war hero type person and generally considered an adept fighter until he meets the desert people.

I appreciate any pointers!

Answer

That would be "The Faded Sun" trilogy by C. J. Cherryh.!

composed of "Kesrith", "Shon'jir" and "Kutath".