Tristan Needham is a mathematician and author of the book Visual Complex Analysis ^{[1]} in which he uses a geometric approach to develop complex analysis (which he says was inspired by Isaac Newton's original geometric approach to ordinary calculus).
He is the son of social anthropologist Rodney Needham, and grew up in Oxford, England. Needham was a student of Roger Penrose at the Mathematical Institute and is currently a professor of mathematics at the University of San Francisco.^{[2]}
Bibliography
Notes

↑ Frank A. Farris, American Mathematical Monthly, vol. 105, no. 6, p. 570: "Visual complex analysis will show you the field of complex analysis in a way you almost certainly have not seen it before". D. H. Armitage, Mathematical Reviews, 98g:30001: "[Needham] has produced a radically new text".

↑ Biography from University of San Francisco – http://www.usfca.edu/artsci/ug/mathematics/fac_staff/needham_tristan.html
