Humpty Dumpty was in fact believed to be a large cannon! It was used during the English Civil War ( 1642 - 1649) in the Siege of Colchester (13 Jun 1648 - 27 Aug 1648). Colchester was strongly fortified by the Royalists and was laid to siege by the Parliamentarians (Roundheads). In 1648 the town of Colchester was a walled town with a castle and several churches and was protected by the city wall. Standing immediately adjacent the city wall, was St Mary's Church. A huge cannon, colloquially called Humpty Dumpty, was strategically placed on the wall next to St Mary's Church. The historical events detailing the siege of Colchester are well documented - references to the cannon ( Humpty Dumpty) are as follows:
June 15th 1648 - St Mary's Church is fortified and a large cannon is placed on the roof which was fired by One-Eyed Jack Thompson'
July 14th / July 15th 1648 - The Royalist fort within the walls at St Mary's church is blown to pieces and their main cannon battery ( Humpty Dumpty ...more

Probably originally a riddle and one of the best known in the english speaking world. Portrayed as an egg. Meaning a person or thing that once overthrown or broken cannot be restored.

Humpty dumpty were eggs in alice in wonderland