n 1993, a cardigan-clad Andrew Wiles delivered the findings of his obsessive seven-year study on “Fermat’s Last Theorem” to a lecture at Cambridge University. When the British mathematician wrote his proof on the blackboard at the end of his presentation, the 200 researchers attending the lecture sat in stunned silence and suddenly erupted into overwhelming applause.

Wiles’ work has since undergone changes – particularly after an error was noted in 1994 – but essentially he managed to definitively prove one of the world’s longstanding mathematical theories. Now, 20-odd years on, Wiles has been awarded the highly prestigious Abel prize.

The prize was awarded to Sir Andrew J. Wiles, 62, on Tuesday by the Norwegian Academy of Sciences and Letters in Oslo. The prize is often referred to as the mathematician’s “Nobel Prize”. Aside from the pride and honor, the award also comes with 6 million Norwegian Krone ($720,000) in prize money.

The mathematical theorem was proposed by Pierre de Fermat in 1637, which states “a^{n} + b^{n} = c^{n}. This equation has no solution in integers for n≥3.” In other words, n can never be more than 2 for the equation to work. It may seem simple enough, but definitive proof of the theory had alluded mathematicians throughout the centuries. You can learn more about the problem in the video below.

Since finding a book about the theorem when he was just 10 years old, the problem stuck in the mind of Wiles and became a lifelong infatuation.

“This problem captivated me,” Wiles told The Guardian. “It was the most famous popular problem in mathematics, although I didn’t know that at the time. What amazed me was that there were some unsolved problems that someone who was 10 years old could understand and even try. And I tried it throughout my teenage years. When I first went to college I thought I had a proof, but it turned out to be wrong,” he said.

While proving the theorem was certainly a weight off Wiles’ mind, the work has widely been described as a landmark in the development of mathematics. Speaking about Wiles, the Abel Committee said: “Few results have as rich a mathematical history and as dramatic a proof as Fermat’s Last Theorem,” adding that his work alone opened up a whole new era of number theory.