Battle of Son Tay Game

From BoardGameGeek:

1883. The French have decided to crush the renegade Chinese Black Flag army. The Eastern forces have taken control of Tonkin and the illustrious Red River. The Black Flag army, along with its Vietnamese allies, have been illusive and put up a fierce resistance. A plan to capture the fortress of Son Tay is put into place in the hopes of a quick end to the war. The shadowy army has fortified Son Tay and is confident that the French will be repulsed. The stage is set... -description from the publisher