When the king who has everything gets married, it’s important to have just the right gift: In this case, the perfect thing was two enormous cannons, equipped to fire monstrous cannonballs weighing in at 330 pounds each, and launching those missiles to an impressive distance of two miles.

The wedding gift for King James II of Scotland arrived eight years late, but what the giver lacked in punctuality he more than made up for in size and power, which must have made the wait worthwhile.

Named for the town in Belgium where she was forged around 1449, Mons Meg is the last surviving of the two enormous guns. Originally given to the Scottish king who was marrying the niece, Mary of Guelders, by her uncle, the Duke Phillip of Burgundy. With a barrel big enough for an adult to climb inside, she is currently considered to be the seventh-largest cannon by caliber in history.

Although she was once used in battle against the English, Meg’s enormous weight – 15,366 pounds – proved unwieldy and difficult to move, eventually restricting her mighty strength to marking momentous royal occasions rather than destroying enemy walls.

Meg also was fired in celebration during the marriage of Mary Queen of Scots in 1558. Her career came to an explosive end in 1681, firing her last shot in celebration of the birthday of the man who would later become King James VII of Scotland and II of England. The barrel’s iron rings burst, and she has been silent ever since.

Although Meg saw some time standing silent vigil at the Tower of London, she was returned to Edinburgh in 1829. Her formidable girth can now be admired outside St. Margaret’s Chapel.