In 125 AD, the Roman Empire, the largest civilization in the world, sprawled from north to south, from Great Britain to Morocco, and east to west, from Iraq to Portugal. Its economy was fueled by war, its focus was conquering, and the military was the main means to achieve expansion. With enormous resources put into the expanding empire, its dirt roads could no longer sustain the growing empire.
Rome engineered itself with a network of paved roadways that eventually covered 400,000 km (248,548.47 miles), with over a quarter considered public roads. Constructing roads for the legions to move with ease and efficiency also helped people and goods travel quickly from one end of the empire to the other. Improved transport of commerce and communication were the key factors in maintaining an empire.
