Explanation: While sieges always provide some amount of advantage to the defenders, usually this is in stalling, rather than destroying, a determined enemy. During the 16th and 17th century AD, however, the Ottoman Turks had adopted then-cutting-edge professionalized military units in the form of the Janissaries (infantry) and Sipahis (cavalry). This advantage in military organization could lead to some very stunning victories, especially against their somewhat hidebound perennial foe, Habsburg-ruled Austria, which still gathered troops on an ad-hoc, feudal basis.