Flashback means the perspective from which the story is told. (or you can put it in another way if you want)
Islam consists mostly of Sunni
The Greeks were the people who implemented and brought jury, democracy, and the Olympics to the world. It was their legacy that made a recognition to the due process of law to defend oneself in a trial. The Olympics was part of their tradition to their gods. Besides these, they were also known for their art, architecture, and theater.
Prorogation is the end of a parliamentary session in the Parliament of Canada and the parliaments of its provinces and territories.