Persia and Egypt.[297] They murmured before Vienna, and without doubt hastened the raising of the siege.[298] THE SUCCESSION TO THE THRONE The Janissaries had no small influence in determining the succession to the throne.[299] There was no law fixing the succession, since neither the _Sheri_ nor the _Kanuns_ provided for such things;[300] but it was a matter of fundamental custom that a prince of the house of Osman should rule, and it was almost as fundamental that a son of a sultan should succeed him. Not until 1617 was the present rule established, by which the oldest male of the royal house is heir apparent.[301] Before that, when a sultan had several sons, the eldest had no inherent right to succeed, as is the practice in Western Europe. The Turkish father naturally desired to choose which of his sons should follow him; and to this end, when he gave them provincial governments, he often placed the favorite nearest the capital. After Mohammed II had issued his famous _Kanun_, by which the son who reached the throne was legally authorized to execute his brothers,[302] a situation of unstable equilibrium arose as soon as the sons of a sultan began to grow up. Each knew that he must either obtain the throne or die soon after his father; hence revolt was almost forced upon a son who found himself placed farther from the capital than a favored brother. When Bayezid II grew old and feeble, his active and warlike son Selim opposed his wish to leave the empire to Achmet;[303] in the end Selim triumphed, and Bayezid, forced to abdicate, met a death that was believed by many not to have been natural.[304] The Janissaries turned the scale in this struggle, and henceforth they were felt to be a dangerous element whenever a sultan came to have more than one grown son. They had a great part in the death of both Mustapha and Bayezid, the ablest sons of Suleiman; indeed, their sympathy for the former was undoubtedly a chief reason in determining Suleiman to execute him, since only thus could his own safety be assured.[305] In the case of Bayezid, the fact that the Janissaries did not support him spelled his doom, even though his father, beyond all precedent, pardoned his first revolt, and though the influence of his mother Roxelana was strong in his favor.[306] Speculation is dangerous; but the Janissaries may have done Western Europe a great service on these occasions. Had either Mustapha or Bayezid come to the throne instead of the drunken and dissolute Selim II, the issue of Lepanto might have been different, a new expedition against Vienna led by a vigorous and idolized young monarch might have succeeded, the Ottoman power might have ruled more widely and permanently than it did, and the decay of the Ruling Institution might have been long postponed.[307]