Frank Foster's Batman was created in 1932. There was no known prior Batman.
Frank Foster worked in the New York publishing business and showed his drawings to publishers of comics from 1937 to 1939. We know he visited DC comics at 480 Lexington Avenue, just a few blocks from where he had lived.
In early 1939, Bob Kane was asked to create a comic book character for a DC comic book at the 1939 World's Fair. It just so happens that Frank Foster was also at the 1939 World's Fair at that exact same time painting a mural! There is a real possibility that Frank Foster and Bob Kane were actually acquainted!
Among all the creatures and characters created in man's imagination, there has never been a known "Batman" like hero prior to Frank Foster's Batman. The closest resemblance might be vampires E.g. Dracula etc. But Dracula was a very different kind of character. It is a stretch of the mind to imagine that DaVinci's winged man was the predecessor of Batman. The resemblance is remote at best. Batman is not supernatural or evil. He has no special powers. Neither does he have wings. He is a regular human who does heroic deeds at night in a bat-themed costume. That was Frank Foster's unique creative concept. That is the character that Batman still is today.
The chance that another artist conceived of the same identical kind of character and who was at the same exact location on Earth at the same moment in history and had the same exact name is an unrelated coincidence is beyond feasibility. It is inconceivable.
The real original Batman drawings you see here were created by Frank Foster in 1932.