It's important to clarify that Albert Einstein is the primary discoverer of the theory of relativity. While others contributed to the development of ideas that led to his work, Einstein is the one who formulated the theory in its entirety.

Here are some individuals who contributed to the foundation of Einstein's work:

* Henri Poincaré: Poincaré made significant contributions to the mathematics and philosophy of special relativity, particularly in his work on the concept of spacetime and the role of the speed of light.

* Hendrik Lorentz: Lorentz developed the Lorentz transformations, which are crucial in understanding how time and space are affected by motion. These transformations are a cornerstone of special relativity.

* Hermann Minkowski: Minkowski developed the mathematical framework of spacetime, which Einstein later incorporated into his theory of special relativity.

It's crucial to remember that these individuals were working independently and in different fields. Their contributions laid the groundwork for Einstein's revolutionary ideas, but it was Einstein who synthesized these ideas and formulated the theory of relativity in its complete form.

So while others contributed, it is accurate to say that Albert Einstein is the sole discoverer of the theory of relativity.