1500s: Henry VIII receives the title “Defender of the Faith” from Pope Leo X for his opposition to Martin Luther, who is condemned as a heretic and excommunicated. After Luther's death, Pope Paul urges Emperor Charles V of Spain to go to war in Europe in an effort to eliminate Protestantism and reunite the Roman Catholic Church. The Church supplies both money and troops for this war.

Today: Religion still plays a substantial role in international politics, but conflicts take place more explicitly between governments, rather than between religious denominations. In some cases, however, fundamentalism and religious fanaticism are linked to terrorism, which has led to the deaths of many innocent people around the globe.

1500s: Henry VIII requires all of his noblemen to swear an oath acknowledging that he is the head of the Church of England. Sir Thomas More, Henry's good friend...