Massive stars are believed to end their lives in powerful explosions called "core-collapse supernovae," thought to be triggered by the gravitational collapse of the progenitor's core into a compact object -- most often a neutron star.  The energy released during this collapse ejects the outer layers of the star, whose interaction with the surrounding medium creates a supernova remnant (SNR).  Meanwhile, the rotational energy of the resultant neutron star powers an ultra-relativistic outflows called a "pulsar wind," whose interaction with its surroundings creates a pulsar wind nebula (PWN).  In this talk, I will discuss how, by studying the properties of a PWN inside the remnant produced in the initial explosion, it is possible to measure / constrain: 

　　the mass of the progenitor star and the initial spin period of the neutron star -- important for understanding how neutron stars are formed in core-collapse supernovae,  

　　the content of the pulsar wind -- critical for understanding how this outflow is generated in neutron star magnetospheres, 

　　and the spectrum of particles accelerated in the PWN -- needed to understand the origin of the some of the highest energy leptons in the Galaxy. 

　　I will present how this can be achieved by fitting the observed properties of such systems with a simple model for their radiative and dynamical evolution, present the implications of our initial findings, as well as describe some future directions of this work.