Ludwig Faddeev made a enormous impact in the mathematical studies of quantum field theory. Just to mention a few: his work with V. Popov on quantum non-abelian gauge theory made the Feynman diagram expansion meaningful, providing necessary tools for later works on renormalizability of Yang-Mills theory, the discovery of asymptotic freedom, and is even used in covariant string theory. Later Ludwig Faddeev revolutionized the field of quantum solitons and quantum integrable systems. He created a very special environment in Leningrad (now Saint-Petersburg) Steklov Mathematics Institute where he supervised tens of currently world-wide renowned mathematicians and theoretical physicists. Three of them are affiliated with Stony Brook: Vladimir Korepin (YITP), Samson Shatashvili (SCGP) and Leon Takhtajan (Dept. of Mathematics). Faddeev was a frequent guest at Stony Brook — he had strong connections with C.N. Yang over many decades both scientifically and personally, and when SCGP was created he had visited and lectured several times. Faddeev taught at numerous international schools and programs, at Les Houches, IAS, and the Simons Center for Geometry and Physics (his last visit was during the 2012 program on gauge theory angle on integrability).
Ludwig Faddeev has won numerous prestigious prizes, including the Dannie Heineman Prize, Dirac Medal of the ICTP, Henri Poincare Prize, Shaw Prize, as well as Lomonosov Medal, Max Planck Medal, and many others. Ludwig Faddeev was the president of International Mathematical Union in 1986-1990, Director of St. Petersburg Steklov Mathematics Institute of Russian Academy of Sciences (PDMI RAS). In 1988 he founded the Euler International Mathematical Institute.
Below are the links to his lectures at the SCGP: