There was no single King of Britain at that time. It was, for the most part a tribal society, with MANY chieftains of or 'kings.'
BC is the same as BCE. From 200 BCE to 50BC is 150 years.
50 years bc is the calendar equivalent of -50. So, as this is 2009, 50bc is 2009 + 50 = 2-59 years ago.
51 BC, maybe?
King Arthur was king of Britain
the population of France in 50bc was 2,500,000
There was no King, Britain was ruled by Queen Victoria.
Edward VII was the king of britain in 1907
The Loyalists stayed true to Britain and the king.
Britain doesn't have a King ! We have a Queen - Her Majesty Queen Elizabeth II
Remembering that there was no year zero, it is 279 years.
Britain
Britain had no King in 1876. Queen Victoria was monarch, with Prince Albert as her consort.