Did the Buddha discover jhana by himself?
I quote an excerpt of this answer from Ven. Yuttadhammo. You may read the answer for details.


  The orthodox view is that samatha meditation was not discovered by
  the Buddha and vipassana meditation was.
  
  The orthodox view is that the Bodhisatta cultivated samatha meditation
  countless times in his past lives before finally discovering
  vipassana.