"The earliest engine was the battering ram, developed by the Assyrians, followed by the catapult in ancient Greece. The Spartans used battering rams in the Siege of Plataea in 429 BC, but it seems that the Greeks limited their use of siege engines to assault ladders, though Peloponnesian forces used something resembling flamethrowers.
The first Mediterranean people to use advanced siege machinery were the Carthaginians, who used siege towers and battering rams against the Greek colonies of Sicily. These engines influenced the ruler of Syracuse, Dionysius I, who developed a catapult in 399 BC.[2]"wiki
THE WALLS ARE TOO WEAK BREAKING THEM DOWN WITH YOUR FISTS PFFT,
The game already has one siege engine, add more and varied types of mounted weapons, and STRENGTHEN THE WALLS. Have been raided 3 times now through my palisades and they stole my tin. Also wouldn't it be nice to build catapults inside your wall and bombard people as they are basing on your Palisades. ^_^