During the 15th century and beyond the Ottomans imported expertise in firearms and gunpowder. A form of Turkish heavy cavalry, known as Sipahi, became the predominating military unit utilized by the Ottoman Empire. The earliest variations of these soldiers were well-armored men on well-armored horses, who typically used a mace as their primary weapon. During the 17th century the Sipahi replaced their archaic weaponry with sabers and pistols, establishing them as a fearsome presence on the battlefield. While European infantry were more than a match for the standard Ottoman infantry, the Sipahi were far superior to any medieval knights.