There are few problems in theoretical physics that have attracted more sustained attention than the Kondo model, a model introduced in 1964 by Japanese physicist Jun Kondo to describe resistance anomalies in metals with magnetic impurities. The Kondo model, and the mathematical techniques that have been developed to study it, has led to improved understanding in an impressive range of problems in physics, from high temperature superconductivity to quark confinement. In this talk I will present an overview of the Kondo model, and summarize my own work involving a mathematical technique based on path integrals