While it's true that others contributed to the development of some ideas that ultimately became part of relativity, it was Einstein who revolutionized our understanding of space, time, gravity, and the universe with his groundbreaking work.

He published two main theories of relativity:

* Special Relativity (1905): This theory deals with the relationship between space and time and how they are affected by motion. It is built on two postulates: the laws of physics are the same for all observers in uniform motion, and the speed of light in a vacuum is the same for all inertial observers.

* General Relativity (1915): This theory extends special relativity to include gravity. It describes gravity not as a force, but as a curvature of spacetime caused by the presence of mass and energy.

Einstein's work on relativity transformed physics and has had a profound impact on our understanding of the universe.