When Christianity spread into Europe it was promoted by the Roman State, and there was immediate dispute about which power – church or state – was superior. When the Roman state disappeared there remained tension between secular and sacred power. Christianity moulded itself to the social hierarchy wherever it spread, but at the same time it was supposed to treat all people as spiritual equals. Nevertheless, those with power needed the backing of the supernatural. How they tried to achieve this, and how they sought to increase their chances of a heavenly eternity, is the subject of this discussion. We can see how it was possible for ruling families to access sanctity, and how they used that sanctity to legitimate their power. Charlemagne is the supreme example of such a ruler, and under his rule Europe comes close to becoming a theocracy. But the church always fought back, seeking spiritual purity. Eventually it won the argument and kept the sacred separate from the secular, but the ultimate consequence of this was the rebellion against the Catholic church that we know as the Reformation. The problem of reconciling the sacred and the secular is one that Christianity has never solved. There are very interesting comparisons and contrasts with Islam here.