History of the Special Theory Relativity (Brief Overview):

Special relativity is commonly attributed to Albert Einstein’s 1905 papers. That is certainly justifiable. However, Einstein swiped the ideas of relativity from Henri Poincare, (who developed and named the principle of relativity in $1895$ and a mass-energy relation in $1900$), without giving him any credit or even mentioning his name.

He may also have swiped the underlying mathematics he used from Lorentz, (who is mentioned, but not in connection with the Lorentz transformation.) However, in the case of Lorentz, it is possible to believe that Einstein was unaware of his earlier work if you are so trusting. Before you do, it must be pointed out that a review of Lorentz’s $1904$ work appeared in the second half of February $1905$ in Beibl¨atter zu den Annalen der Physik. Einstein was well aware of that journal since he wrote $21$ review journals for it himself in $1905$. Several journals were
in the very next issue after the one with the Lorentz review, in the first half of March. Einstein’s first paper on relativity was received in June $30$ $1905$ and published on September $26$ in Annalen der Physik. Einstein had been regularly writing papers for Annalen der Physik since $1901$. You do the math. In the case of Poincare, it is known that Einstein and a friend pored over Poincare’s $1902$ book “Science and Hypothesis.” In fact, his friend noted about that and both kept “breathless for weeks on end". So Einstein cannot possibly have been unknowing of Poincare’s work.

However, Einstein should not just be blamed for his boldness in swiping most of the ideas in his paper from then more famous authors, but also be
commended for his boldness in completely abandoning the basic premises of Newtonian mechanics, where earlier authors wavered. It should also be noted that general relativity can surely be credited to Einstein's fair and square. There is a possibility that the mathematician Hilbert may have some partial claim on completing general relativity, but it is clearly Einstein who developed it. In fact, Hilbert wrote in one paper and concluded that his differential equations seemed to agree with the “magnificent theory of general relativity". Which was established by Einstein in his later papers. Clearly, Hilbert himself agreed that Einstein established general relativity.