Hawking was born exactly 300 years to the day of Galileo’s death and died on the anniversary of Einstein’s birth. And just as it was Galileo who experimented with gravitational physics, and Einstein who created new theories of gravity and the atom, Hawking devoted much of his energies to link them into a unified theory. He did this by thinking about what a black hole would look like and how it would behave if it were the size of an atom.(1)
It should also be noted that he died on March 14, 2018. That was Pi Day 3.14!
(1) https://airandspace.si.edu/stories/editorial/stephen-hawking-explorer-universe