Who invented the first steam engine ?

When it comes to the invention of the first steam engine , many people would think of James Watt immediately. However , he is not the first one to invent such precise machine. Actually,  Thomas Newcomen (February 1664– 5 August 1729)  invent the  steam engine 70 years earlier than Watt . But what's more ,  Hero of Alexandria invented the first recorded steam engine in human history.

The prototype of steam engine

Actually, the prototype of steam engine can be traced back to ancient Greek time. It is called Aeolipile rather than steam machine. The details of the Aeolipile is shown as above.

Why only James Watt is praised?

Well, Although he didn't develop the first steam engine, he managed to modify the primitive design of the Aeolipile which puts steam machine into practical use . With his modification, the progress of industrialization has advanced so much that we should revere him. He plays a vital role in industrialization and he is hailed as the founding father of industrialization. So people would like to remember him and so his name is used as the SI power unit (Watt)