Dermot O'Leary, Arthur Williams and Lucy Betteridge-Dyson examine Waterloo, one of the most famous battles in British history, as it unfolded over 48 hours in 1815. It was a battle that would pave the way for a new Europe, cement Britain's position as a world power, and pitch two famous generals, Napoleon and Wellington, up against one another. To capture the stunning story of Waterloo's twists and turns, the team focuses on Marshall Michel Ney - one of Napoleon's top commanders - and Major General Sir William Ponsonby, who led the British cavalry brigade in battle.

Dermot O'Leary, Arthur Williams and Lucy Betteridge-Dyson examine the final 48 hours of the Battle of the Somme, which raged for over four months. Dermot spends time in reconstructed trenches and meets the descendants of a Glasgow soldier who was one of just 15 men in his battalion to survive, and Lucy meets a bomb disposal team who are still uncovering shells from the conflict to this day.

In the first episode, they tackle Dunkirk and two key days during the evacuation of British soldiers that prevented a German triumph. The heroic actions of one ship, HMS Worcester, act as a window into the wider story of the safe retreat of thousands of men.