At the start of the 20th century, the battleship was the key naval vessel, escorting convoys and overpowering the enemy. But over the course of two world wars, technology raced ahead, drastically changing their role from flagships of the fleet to floating artillery vessels. Revisit some of the mighty battleship's greatest triumphs and tragedies and witness tales of heroic acts and daring missions, from the Battle of Jutland to the sinking of the HMS Royal Oak to the D-Day invasion.