One of the world's leading mathematicians, Prof. Sir Michael Atiyah, died at the age of 89.
Sir Michael, who worked at Cambridge University Before retiring, he made outstanding contributions to geometry and topology.
Sir Michael received the highest honors in mathematics, a Fields medal. He died on Friday.
His brother Joe told BBC News he was one of the most important mathematicians of the 20th century.
"He has been described to me by more than one math professor as the best mathematician this country since Sir Isaac Newton," said Atiyah.
. Sir Michael was also a former president of the Royal Society, one of the highest honors a British scientist can receive.
Professor Venki Ramakrishnan, the current president of the Royal Society, described him as a "great mathematician".
"Sir Michael Atiyah was also a wonderful person who, as President of the Royal Society, proved he is a true internationalist and a keen supporter of investing in talent," he added.
Sir Michael was best known for his involvement in a branch of mathematics, topological K theory, and the Atiyah Singer index theorem.
His research also included deep insights into mathematical concepts known as "vector bundles".
His work in these areas has helped theoretical physicists improve their understanding of quantum field theory and general relativity.
He was also an occasional poet ̵
"Sir Michael Atiyah was a dear mentor, friend and role model, unsurpassed in mind and energy," he said.
"His inheritance in mathematics and physics will last forever, his death is a terrible loss, and we extend our deepest condolences to his family.
" He will be greatly missed by friends and colleagues around the world. "