What's the Name of That Book??? discussion

Plot Details:
The man is going to a conference (I think it might be a medical one but this could be incorrect), aliens using some sort of invisiblity/intangibility thing have a systems failure and accidentally destroy the plane. They capture the survivors and give them the option of being euthanized or sent to other planets. These planets have humans on them and the aliens dont know why.
Man chooses to be sent to the other planet, which has a lower level of technology. Gunpowder is around but rare and has to be imported, sailing ships are common, no electricity, etc.
Man is dropped, naked and unconscious, at a beach near a monastery(?) that works as doctors and healers for the local population. He doesn't know the language..
Man eventually starts learning the language by talking with a local laborer who work at the monastery
Eventually shares the technologies of Ether with the locals. Later on shares things like Lamp Oil, semaphore, the production of gunpowder, cannon canister shot and cannon production.
Marries one of the local women, I believe she was the daughter of a local leader?
Gets pretty rich, ends up building a house near the beach to live with the wife.
Eventually imperial colonists arrive and start causing trouble, the protagonist helps by sharing the technologies and attempting to lead using more modern tactics.
Eventually gets a horse who he names Mr.Ed. Sings the Mr.Ed theme song in english around the various locals at one point.

Misc Info:
Listened to on Audible around 2014-2019
Author was a man
Book was released that decade I believe


This is my first post and my first time using this site, apologies for any formatting errors or similar things. Thank you.

This sounds familiar. I'll do some searching to see if I can find it.

This sounds very much like Cast Under an Alien Sun by Olan Thorensen, the first of a series ofabout six or so books.

Sue wrote: "This sounds very much like Cast Under an Alien Sun by Olan Thorensen, the first of a series ofabout six or so books.
"

That's certainly the one I was thinking of.