Harlequin (The Grail Quest, #1)
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Set in the 100 years war, starts with a holy relic being stolen from a small church by a group of French.
Later, the main character is in the army as an archer, and discovers the secret behind the relic and how it relates to him.
In terms of characterisation it is very similar to Sharpe novels, although the main character is more of a Hogan to his leaders Sharpe.
The battles and skirmishes are well written, and it leads nicely into the next book.