How many years between 1964 to 2011?

What civilization made the water tank and citadels? Who invented shoes and when where they invented? What is the difference between the purpose of a source and its context? How many years is a half of a millennium? Who invented the MODERN day toilet? What did Romans do to Christians who refused to worship Roman gods? What is a group of manors owned by a lord? Why did western Europeans go on crusades? What is the origin of the word modern? What did Romans establish in 509 BC? Is this old Roman adage correct Fear not Rome for the serpent lies coiled in Naples....? When was the beware the ides of march? What part of china did Kublai Khan Conquer? Who led the dutch revolt of the 16th century? What was one of the main contributions of the middle ages to Christianity? Was BC renamed? Where were the Vilings from? What western middle name goes with Jackie? What is the most lasting contribution left by the Romans? How did Claudius die?