English Political Geographer Sir Halford Mackinder came up with his heartland theory in the 1904. He submitted his theory to the Royal Geographic Society. 
The theory came about due to the fact that Russia was a huge nation at this point in time and even though slightly backwards in some respects at the same time they still held a vast empire yet to be defeated in battle.
The theory came about due to the fact that Russia was a huge nation at this point in time and even though slightly backwards in some respects at the same time they still held a vast empire yet to be defeated in battle. 
The theory states that all of world power rotates around the pivot area. So the pivot area is the power stronghold of the world; it will always have power but the power in the areas around it will change. The pivot area places an importance on Eastern Europe and the Russian Empire.
Many believe that Mackinder's Heartland Theory was used by Adolf Hitler and the Nazi's as his way of planning a world takeover, however, how far this was used is yet to be fully deciphered.
Mackinder labelled Europe, Asia and Most of Africa the World island. It was in his opinion the land mass all connected together that held the most power. The offshore islands (including Britain and Japan) held the next amount of power, followed by the outer islands which are the North and South American and Australia.
Although the theory was proved successful, from World War II
onwards the idea lost its significance. Since Russia the so called heartland of power crumbled to the German armies and the Japanese islanders ended up conquering vast areas of Asia which is connected to the World Island. Also the theory itself implies a weakness and insignificance of sea war craft which played a vital role in World War II.
onwards the idea lost its significance. Since Russia the so called heartland of power crumbled to the German armies and the Japanese islanders ended up conquering vast areas of Asia which is connected to the World Island. Also the theory itself implies a weakness and insignificance of sea war craft which played a vital role in World War II.