One primary cause for the decline of the Empire was the decline of the Sultanate. The Sultanate was a powerful organization where the sultan would chose a capable successor from his many sons. Over periods of time the sultanate weakened gradually. The weakening of the empire began late in the ruling of Suleyman the Magnificent. Although he was the height of the Golden Age, Suleyman became less concerned with the affairs of state added to that his two qualified successors went against him, they were later executed. As Selim II became Sultan he did not have much experience in the running of the government. He was fond of physical pleasures rather than taking the governing responsibility seriously. After him the decline of the Sultanate continued. Because the brothers of the Sultans were restricted in the harem, they became incompetent. Another reason to the decline of the empire was that the Sultans deserted the tradition of training their sons in related affairs and government. The collapse of the empire focused mainly on the corruption of the government's control over the empire. Added to this problem was the major factor which was the change in the balance of power. Because of the Ottoman military division called the janissary kept fighting and always conquering new lands and became the most powerful state in the world. As time passed the janissaries and their fighting methods became old-fashioned and no longer became a army that was unmatched. In the end, the Ottoman Empire collapsed, the government declined with the degeneration of the sultanate as well as the Ottomans failed to industrialize and the empire was destroyed when war overwhelmed it during World War I.