Let $\displaystyle S$ be the circumcircle of a triangle $\displaystyle ABC$. Tangents are drawn to $\displaystyle S$ at $\displaystyle A, \, B$ and $\displaystyle C$. These tangents meet at points $\displaystyle P, \, Q$ and $\displaystyle R$.

Prove that the Euler line of triangle $\displaystyle ABC$ passes through the circumcenter of triangle $\displaystyle PQR$.