What is the Biblical and historical basis for Christian pacifism?

My understanding is that early Christians were generally pacifists. Today (at least in the U.S.) Christian pacifists are a bit hard to come by. Many quote [Romans 13:1-3](http://www.biblegateway.com/passage/?search=Romans%2013:1-3&version=NIV) to support Christian involvement in war: > **1** Let everyone be subject to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. **2** Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves. **3** For rulers hold no terror for those who do right, but for those who do wrong. Do you want to be free from fear of the one in authority? Then do what is right and you will be commended. In light of this verse, and other Biblical or historical evidence, *what is the case to be made for Christian pacifism?*