The 1622 janissary revolt against the ottoman leadership was one of the situations that marked the beginning of the decline of the empire, but by what awareness and by whom?

Sultan realized expanded empire beyond ruling ability

Explanation:

The Janissaries were elite infantry units that formed the Ottoman Sultan's household troops, bodyguards and the first modern standing army in Europe.

In 1622, the teenage Sultan Osman II, after a defeat during war against Poland, determined to curb Janissary excesses. Outraged at becoming "subject to his own slaves", he tried to disband the Janissary corps, blaming it for the disaster during the Polish war. In the spring, hearing rumours that the Sultan was preparing to move against them, the Janissaries revolted and took the Sultan captive, imprisoning him in the notorious Seven Towers: he was murdered shortly afterwards.

The empire was to big for one man to rule it efficiently, this event was a sign of this.

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.