It's the morning of June 14, 1645, in a valley in Northamptonshire, England.

Sitting on horseback, on the crest of a ridge, 46-year-old Oliver Cromwell stares down the slope at a battle

unfolding below. Thousands of cavalry are formed up around him, their horses snorting and pawing at

the ground with impatience. Cromwell grips his sword tight. He's waiting for the right moment to

give the command and send his men down the hill to join the battle.

It's three years into a brutal civil war.

The conflict between King Charles I and the English Parliament has torn the country apart.

Charles believes that as king, he is appointed by God and should wield absolute power over his subjects.

But the parliamentarians believe that the English people should have some say over how they are governed.

The course of the war has ebbed back and forth, but today the main armies of each side are meeting in battle.

And for the commander of the parliamentary cavalry, Oliver Cromwell,

it's an opportunity to strike a decisive blow against the royalists. From his position on the ridge, Cromwell, it's an opportunity to strike a decisive blow against the Royalists.

From his position on the ridge, Cromwell sees that the Royalist infantry has over-extended itself.

It's pushing the parliamentary infantry back, but that has left its flank exposed.

These conditions are perfect for a cavalry charge.

Cromwell shouts out his orders, and all has won, his well-drilled cavalry surges forward.

The earth churns beneath thousands of pounding hooves, galloping downhill with him.

Conwell raises his sword above his head, lets out a guttural battle cry.

A royalist infantry is pinned down in their fight with the parliamentary foot soldiers.

They can't turn and form lines to defend themselves before Cromwell's horsemen smash into them in a devastating collision of horses, men, mud, and metal.

The Battle of Nesby will prove pivotal in the English Civil War.

The overwhelming victory for Oliver Cromwell and the parliamentary army

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