On 14 October 1808, Napoleon persuaded Herzog Peter Friedrich Ludwig of Oldenburg to join the Confederation of the Rhine by the Treaty of Erfurt – the military contingent to be maintained by the duchy was set at an infantry battalion of 800 men in six companies. Similarly, Friedrich August, Herzog of Nassau, was charged, under the terms of the treaty with co-ordinating and organising the military efforts of all the tiny states of its neighbours. In this fine addition to Osprey's Men-at-Arms series, Otto Von Pivka details the campaign history and uniforms of Napoleon's Nassau and Oldenburg allied troops.