Baron of the Middle Counties (Cast in Time, #2)

An Engineer finds himself in an Alternate reality, Cornwall, in the year 715 A.D. He awakens in the body of a young Baron.
A retired Lieutenant General, former head of the Army Corp of Engineers, lies dying at the age of ninety-two. Leading a full life, he is a decorated veteran of World War II, Korea, and Viet Nam.
After a long illness, he lies dying. His last thought is, "What a waste of such wonderful knowledge."
As he fades to black, the fun begins. He is to build a modern civilization without being burned as a witch!
The series continues with the Barony of Owen-nap being attacked from all sides.