When Martin Luther nailed his Ninety-five Theses on the door of the Castle Church in 1517, the hammering in Wittenberg was heard across Europe. As we commemorate this event five hundred years later, the echos are still reverberating throughout Western civilization. This brief backgrounder explains for Lutherans and non-Lutherans why the Protestant reformation happened, what it meant at the time, and why it still remains relevant today - half a millennium later. The book focuses on the historic roots and context of the Reformations in Germany and England, as well as the key spiritual concepts behind them. Over 300 footnotes serve as pointers to original sources, many available online and for free. A kick-starter for your own Reformation research!