500s: Britain is fractured by competing kingdoms and beset by Saxon invaders. Britain's rulers briefly unite to drive back the Saxons, but the island is ultimately overrun and settled by the foreigners.

1950s: Britain is considered a venerable, established civilization. Americans consider it the "old world," with dated political practices such as colonies and a monarchy.

Today: The last of the British colonies in Africa received its independence in the 1960s, and the British Royal Family has only symbolic power.

500s: The identity of the actual King Arthur, if there was one at all, is unclear because written records are scarce and communication between different countries is almost nonexistent.

1950s: Television increases in popularity throughout the decade, allowing politicians to communicate directly with the general population.

Today: Politicians still speak directly to the public via television, but educated viewers are wary of image manipulation...