What Inspired Einstein to Develop the Concept of Spacetime?

[Macrobe]

I have done quite a bit of research regarding the subject of spacetime, but what I want to know is, what was the reasoning behind it? I understand the subject and agree with it, but I want to know how Einstein came about the idea.

 

[PeterDonis]

Einstein learned of it from Hermann Minkowski, who had been one of his professors. The Wikipedia article on Minkowski spacetime gives a brief overview:

http://en.wikipedia.org/wiki/Minkowski_spacetime#History