Albert Einstein's explanation to the curvature

Albert Einstein's explanation to the curvature 
After the introduction of his theory of special relativity in 1905 Einstein wants to understand the concept of Gravitation in more basic way so he decided to read the Princpia Mathematicia so that he would find the true reason of Gravity.But unfortunately Einstein didn't find the reason of gravitation. So he decided to generalize the concept more deeply and use his brilliant brain to pop out a reason of gravitation. For this he required some advanced mathematics which so that it will apply to his physical assumption. Then he found Riemann' s explanation and curvature mathematics which really shocked him. Riemann did every thing right in the mathematics of curvature but didn't had a physical explanation towards it. That's made a golden chance to Einstein to publish his theory of general theory of relativity
So his explanation was that the every mass creates a distortion in the curvature. He said that space is something like a stretched membrane which allows to stretch itself when any sort of mass came in contact with it