William Jones, mathematician from Anglesey, North Wales
A noted mathematician, published author and early naval navigator. First to use 'Pi' (1706) as a mathematical symbol.
He was a friend of Isaac Newton and Edmund Halley. Father of William Jones the philologist who identified the Indo-European language group which connects many early languages (Sanskrit, Greek, Latin - even Welsh) together.
Connection: Born in Llanfihangel Tre'r Beirdd.
The UL website goes on to say "William Jones was important in his lifetime primarily for three things: he was the first person to use the Greek letter π in its modern sense; he had acquired such a significant archive of manuscripts that he was appointed to the Royal Society committee, to investigate the invention of calculus; and he was influential as communicator in a network of mathematicians, astronomers and natural philosophers in the early eighteenth century."
Vice President of the FRS.
Robert Recorde, Noted mathematicians.