Actually, that is a very common misconception! Albert Einstein did **not** win the Nobel Prize for his theory of relativity. 

He was awarded the **1921 Nobel Prize in Physics** officially *"for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."*

Here is the story behind why this happened:

**1. What is the Photoelectric Effect?**
In 1905, Einstein published a paper explaining the photoelectric effect—the phenomenon where light shining on a metal surface causes that metal to emit electrons. At the time, light was believed to be a continuous wave. Einstein proposed that light actually travelled in tiny, discrete packets of energy (which we now call photons). This discovery was absolutely ground-breaking and laid the foundation for the entirely new field of **quantum mechanics**. 

**2. Why didn't he win for Relativity?**
Einstein published his Special Theory of Relativity in 1905 and his General Theory of Relativity in 1915. By the early 1920s, he was a massive global celebrity because of it. So why did the Nobel committee ignore it?
* **It was too controversial:** At the time, relativity challenged the fundamental Newtonian views of the universe. Even though the famous 1919 solar eclipse produced experimental evidence supporting General Relativity, many scientists were still highly skeptical. 
* **Bias against "pure theory":** The Nobel Committee for Physics at that time heavily favored experimental physics over theoretical physics. They felt relativity was too mathematical and abstract.
* **Political and personal friction:** There was a certain degree of anti-Semitism and nationalism in the scientific community following World War I, and some committee members actively campaigned against Einstein.

**The Compromise**
By 1921, the pressure to give Einstein a Nobel Prize was immense—he was undeniably the most famous and important physicist in the world. A Swedish physicist named Carl Wilhelm Oseen came up with a brilliant compromise: nominate Einstein for the photoelectric effect. 

Unlike relativity, the photoelectric effect had recently been proven through rigorous physical experiments by Arthur Compton and Robert Millikan. This allowed the Nobel committee to finally give Einstein the prize he so clearly deserved, while saving face and avoiding explicitly endorsing the still-controversial theory of relativity. 

Interestingly, when Einstein gave his official Nobel acceptance lecture, he mostly ignored the photoelectric effect and talked entirely about the theory of relativity anyway!
