Terrifying plague kills millions Chinese oust Mongol rulers Ottomans carve out a new empire The sternpost rudder, a new device for steering ships, is adopted Violence in Japan threatens stability Tatar leader Timur controls much of Asia African emperor's travels bring glory to Mali

4. The sternpost rudder, a new device for steering ships, is adopted European shipbuilders are enthusiastically replacing their awkward, inefficient steering oars with a new fin-shaped device called a rudder. Attached to the ship's stern, a rudder enables sailors to steer more easily, even in heavy seas. The rudder is also capable of effectively steering ships larger than those that could be managed with steering oars. Only time will tell what further impact this innovation will have on sea travel. View from Today