The Company by K.J. Parker.
I usually like Parker's non-fantastic fantasies (The Folding Knife, The Hammer, the "Engineer" trilogy), but this one didn't do much for me. The plot is on rails towards a more-or-less inevitable ending and the way Parker slowly doles out the characters' backstories, a device that usually works well for him or her (Parker is pseudonymous), just conceals how flat and thin they really are.
The book's about four veterans, war heroes, who've been out of the army for a decade and are drifting unhappily through life. Their beloved commanding officer comes back and talks them all into a plan to start a small colony on an island he's found and effectively stolen from the army. They buy a ship, hire a crew, and set sail. Things go wrong more or less from the start, until they find that the island is home to a huge gold strike. Then the real trouble starts, as greed and paranoia start to set in and old slights (via those aforementioned backstories) take on new weight.