Who was the first major Christian figure to popularize a figurative interpretation of Genesis? I assume that the church for a majority of its existence has assumed a plain interpretation of Genesis. However it's easy to see the church of the last 50 years adopt a more figurative interpretation of Genesis, presumably to coincide with popular scientist's standpoint that everything was created slowly and that human's are an evolved species.

I'd consider these to be tenets of a literal Genesis view:


God created the heavens and the earth in 6 literal, sunrise-sunset days
Birds, land-creatures, sea-creatures, plants, etc...were all created within this time frame
Adam and Eve were the first created people, created on the 6th day, and are the sole parents of humanity.


So it seems like the new popular tenets are these:


The "days" in Genesis 1 represent longer periods of time.
God guided evolutionary process.
Adam and Eve were 2 of many existing humans at the time and were evolved from a common ancestor to apes.


Can anyone pinpoint the person(s) or event(s) within the church that caused it to accept a more figurative view? This is not a question as to whether a figurative Genesis interpretation is right or wrong, but simply to see from where the normalcy of that belief came. I assume it would have happened in the last 200 years so it shouldn't be too hard to find the flagship for this.
I think it's clear that your assumption is wrong, and that figurative interpretations of the Genesis were always common amongst scholarly interpreters, such as for example St. Augustine. At the very least, he thinks that the transgression in the Garden of Eden was in fact of a sexual nature, and therefore the account as it is, is figurative.

Further, we are somewhat well aware that medieval culture in Europe was steeped in allegorical thinking. Even something like a bestiary, a compendium of beasts, would include several allegorical beasts as stand-ins for vices, for specific historical characters, peoples, etc...

To make a further point however, the idea that figurative, allegorical and literal interpretations of the same text were mutually exclusive is very modern idea.

http://en.wikipedia.org/wiki/Allegory_in_the_Middle_Ages

http://en.wikipedia.org/wiki/Allegorical_interpretations_of_Genesis