2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/87696This article provides a unified introduction to the theory of electron and proton spin polarisation in storage rings and it provides a common starting point for the written versions of the four talks that I gave at Monterey22 pages with 1 embedded figure. Latex. Paper 1 of a set of 5 . others are physics/9901041 physics/9901042 physics/9901043 physics/9901044Accelerator PhysicsClassical PhysicsQuantum Physicstext