Blouet, one of Mackinders biographers, the membership of the Royal Geographical Society consisted of men with a general interest in the world and its affairs, officers from the army and navy, businessmen, academics, schoolteachers, diplomats, and colonial administrators.
Policy makers and scholars remember them now mainly for the seemingly simple formula that control of Eastern Europe would bring command of the Heartland, thus control of the World-Island (Eurasia), and ultimately the world.
Halford Mackinder - New World Encyclopedia
The following quoted passage is from a letter written by British imperial strategist Halford Mackinder to the British Royal Geographical Society. The letter was entitled, "The Geographical Pivot of History."