Catholicism has always been a huge religion, and has been in control of the world for previous ages. For that reason, they were the ones who could dictate when to start the timeline, and chose the birth of Christ as that starting point.
Hey! Christian unity ended in western europe! Have a great day!!
Political machines created cycles that turned, like gears.
The war which occurred in the mid-1800s that weakened the economy of the Ottoman Empire was the Russo-Turkish War, led by the Turks on one side, and Russia, Bulgaria, Romania, Serbia, and Montenegro on the other.
<em>Liberalism is the belief that people should be as free as possible from government restraints.</em>
Hoped I helped:D