Mightier Than The Shovel Achievement/Trophy Guide - Find the hidden Cavalry Sword and take down an enemy on the French countryside in the campaign.
This achievement/trophy can be earned in the 'Mud & Blood' campaign when you reach the chapter called 'Breakdown' which will task you with looking for spark plugs for you tank. After collecting your first set of spark plugs continue down into the town by following the part out of the little village that you were just in and once you reach a wide open street you will see a guard coming down it. Kill the guard then quickly get inside the building or the enemy upstairs will spot you. You will see the sword on the floor to the left as soon as you enter the building so pick up the sword and kill the enemy that will be walking down the stairs in that building.
Here is a video guide for you if you happen to get lost or stuck.