Which religious leader is said to have found Enlightenment while sitting under a tree?

Arohanui, Every sect (of which, there are many) of Buddhism views it as an overall philosophy with a daily practice of medication and/or chanting, usually a recitation from one of the Sutras that Siddhartha wrote after becoming "The Buddha". I was born/raised a Nichiren Buddhist who chants Nam-Myoho-Renge-Kyo, so I only speak to its qualifications as a religion. And it can be called a religion since we believe "God" exists in every person. We don't seek happiness outside ourselves, but look within.

One of the Greatest Souls/Teacher's in world history.

I am not religious, but Buddha and his thing seems like the best religion. Everything's always about peace and love. No one ever launched a bunch of bombs at some guy sitting under a tree.