A unit with this promotion can attack after moving.
As the battlefield became more fluid in the 1700s in Europe, various nations created horse artillery – light, fast-moving, and fast-firing artillery that could provide mobile support, sort of a hybrid of cavalry and cannons. Introduced by the Swedes during the Thirty Years' War, horse artillery became a staple for all the "modern" armies, and the guns themselves became larger and yet lighter. Thus, battlefield cannon evolved ... unfortunately, that meant that the crews needed to be better trained. But it wasn't until 1915, when Britain established the School of Instruction for Royal Horse and Field Artillery (the world's first) at Larkhill that such training was available, making its graduates "experts" in fire-and-move artillery tactics.