Leonard Roth should not be confused with Klaus Roth.
Leonard Roth (29 August 1904 – 28 November 1968) was a mathematician working in the Italian school of algebraic geometry. He introduced an example of a unirational variety that was not rational (though his proof that it was not rational was incomplete).
Roth was born in Edmonton, London. He was educated at Latymer Upper School, Dulwich College and Clare College, Cambridge, where he graduated as a Wrangler in 1926.[1] He died in 1968 in Pittsburgh, Pennsylvania. His sister was Queenie Roth, literary critic and wife of F. R. Leavis.