If you ask me, then that would be Siddhārtha Gautama. I mean he lived in 450 CA, till 370CA, what was a very difficult time. He was a prince he left his palace to wounder around between his people.
Then he when alone into the jungle and stayed there for 6 years, until he reached enlightenment, or to say another point of view. Since then he walked around to villages, to spread his teachings to reach spiritual freedom.
What is also very difficult in those days, because people would kill for less, and he done that until he was 80 and died peacefully below a tree, with 500 friends gather around him.
So to end like that in those days could only be done with high intelligence and there for i think he is the most intelligence person ever existed, and not only because what he had achieved, but more about his life totally, they call him the Buddha!
I believe this is more opinion based, due to the fact that true intellect is a difficult thing to measure.
In my mind, there are different dynamics to intelligence. You have overall "awareness" or "wisdom" , and you have what some may refer to as "book smarts".
There is a clear division of these two dynamics. Take for example, minds like Kim Peak, who was the real character depicted in the move The Rain Man. This man had a mind that was more closely compared to a computer hard drive than a normal human memory. He would retain about 98 percent of everything he visually, and auditorily digested. This man could not tie his own shoes or dress himself without help though, so even though he had a massive capacity for remembering things, one might say he had no problem solving skills whatsoever, which would not be a very good basis for intelligence if you ask me.
Then you have minds like Albert Einstein, who although had a level of scientific intellectual understanding that is difficult to fathom, he lacked in social skills, and was likely on an autistic spectrum, which in turn limited his intelligence in the opinion of some.
In my humble opinion, one of the greatest minds we have ever seen, was Stephen Hawking. I maintained a great deal of respect for this man, due to the level of "insight", and "wisdom" that was commonly associated with his name, as well as his ability to live with amyotrophic lateral sclerosis in a fashion where he maintained his dignity, as well as showed his massive ability to problem solve. Just look at the text to speech system that was designed by a dear friend of his through his guidance. He was truly a miraculous human being in every way, and I will never forgot his chilling warning about where we are heading with AI. I think it's safe to say I favor minds with great wisdom and problem solving skills, over minds that have high retention rates.
3 people who are considered the smartest in the world.
1. Stephen Hawking
Stephen William Hawking is a theoretical physicist. He is a holder of the Mathematics professorship at Cambridge University (Lucasian Professor of Mathematics), as well as a member of Gonville and Caius College, Cambridge.
He is known for his contributions in the field of quantum physics, mainly because of his theories about cosmological theory, quantum gravity, black holes, and Hawking radiation. One of his writings is A Brief History of Time, which is listed on the Sunday Sunday Times bestselling list for 237 consecutive weeks.
Despite tetraplegia due to amyotrophic lateral sclerosis, his scientific career continued for more than forty years. His books and public appearances make him the most famous academic celebrity and theoretical physicist in the world.
In addition, he is also known for his proof of Albert Einstein's theory.
2. Isaac Newton
Isaac Newton was a physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian from England. He is a follower of the heliocentric school and a very influential scientist throughout history, even said to be the father of classical physics.
His book Philosophiæ Naturalis Principia Mathematica published in 1687 is considered the most influential book in the history of science. This book lays the foundations of classical mechanics.
In this work, Newton describes the law of gravity and the three laws of motion that dominate the view of science about the universe for three centuries.
Newton managed to show that the motion of objects on Earth and other space objects is governed by a set of the same natural laws. He proved it by showing consistency between Kepler's laws of planetary motion and his theory of gravity.
His work finally left the doubts of scientists about heliocentrism and advancing the scientific revolution.
3. Albert Einstein
Albert Einstein was a theoretical physicist who was widely regarded as the greatest scientist in the 20th century. He put forward the theory of relativity and also contributed greatly to the development of quantum mechanics, statistical mechanics, and cosmology.
He was awarded the Nobel Prize in Physics in 1921 for his explanation of the photoelectric effect and his devotion to Theoretical Physics.
There is someone who is considered the most intelligent man in history: William James Sidis. And it is estimated that his IQ was 350 to 400.
Stephen Hawking had a coefficient of 160, currently Terence Tao has the highest coefficient in the world with 230.
Let's talk about the deeds of Sidis.
At the age of six, he could speak 9 languages fluently: English, Russian, Italian, Latin, Armenian, Greek, Hebrew, French, Turkish and German.
Also, at age six he developed an algorithm that predicted or indicated the date of a historical event that would have happened depending on the necessary information.
Before twelve, he had already corrected doctoral theses and works of mathematicians such as Vermilye Hungtiton.
At eleven, he had a master's degree in mathematics and planetary studies.
From the ten, he gave scientific lectures at universities like Harvard.
At six, he presented the Harvard Medicine Entrance Examination and approved it as the highest grade.
At seven, he did the same, presented a right entrance exam and passed it with perfect grade.
At nine, he took an entrance exam for linguistics and passed it with a perfect grade, but he took it seriously and graduated that degree with a perfect grade.
At sixteen, after graduating in linguistics, he presented again the entrance examination of law to study that career, which graduated with honors.
By age five, he had written four books: two of human anatomy and two of astronomy.
A year and a half after his birth, he could read the newspaper and understand it perfectly.
At age eight, he created his own language, Vendergood. This language is one of the most complete ever made in history and wrote a book about this language.
As an adult, he learned Portuguese in one day.
He mastered fifty languages perfectly. But beware, he understood all the languages spoken in the world, was able to translate or speak in any known language.
He published more than three hundred books (with different pseudonyms): books of mathematics, physics, astronomy, languages, botany, etc. all first level.
In essence, this man in a day could learn everything that was proposed. He could excel in all the areas of knowledge he wanted.
regards my friend