The 12th of February 1809 saw the birth of two of the most influential men of any century.

Charles Darwin revolutionised everything we understand about biology and articulated perhaps the most important thought ever to occur - the idea of the evolution of species through natural selection. His books on the subject are paragons of observational science and critical self-examination.

Across the Atlantic, Abraham Lincoln also came into the world, destined to preserve the most important experiment in human liberties. The extraordinary courage and principle he brought to politics has rarely, if ever, been matched.

What a day, 200 years ago. What an extraordinary day.