Are you puzzled about the violence of the Islamic State, how killing and torture can be justified by religious doctrines? Have you thought that Muslim violence today echoes Christian violence in the Crusades and the Inquisition? If so, you likely welcomed President Obama’s comments at the National Prayer Breakfast in early February.

If you are among those who reflexively criticize anything Obama says, or are enamored of right-wing media bloviators, you may have gotten indigestion at Obama’s statement that in “the Crusades and the Inquisition…people committed terrible deeds in the name of Christ.”

Former Republican governor of Virginia, Jim Gilmore, said Obama’s comparison of Muslim and Christian violence was “the most offensive [comment] I’ve ever heard a president make in my lifetime.” Gilmore added, “He has offended every believing Christian in the United States.” [Question: are there non-believing Christians?] The president of the Catholic League, Bill Donohue, stated that Obama’s comparison was “insulting” and “pernicious.”

What are these people upset about? One wonders whether Gilmore and Donohue really don’t know the history of Christianity, or if they believe this history should be hidden. Given the sad state of education in the United States, the possibility of their ignorance exists. Equally sadly, the possibility exists that they know this history and want to hide it.

Historical records show that Christianity was very violent during long periods of its development. The horrors of the Crusades and the Inquisition, to which Obama referred, are demonstrated in official church documents. The Crusades were a 300-year long series of church-sponsored military expeditions to eject Muslims from the “Holy Land.” The Inquisition was a 400-year long, multinational church network of terror against all other religions and especially against “infidels” (non-believers) and “heretics” (people with “wrong” beliefs).

For example, under Pope Innocent III, the Christian powers waged a war of terror against “heresy” in what we now know as southern France. One million people were killed in 15 years. The Christians wiped out whole towns at once. When the “soldiers of Christ” asked the Bishop of Cocteau what they should do with the Catholic citizens of one town, the bishop said, “Kill them all, God will recognize his own.” The papal legate thereafter notified the pope that the entire population of the town—20,000 people—was put to death.

The violence of Christendom extended to “heathens” (people who have not heard the “word of Christ”) in the “New World.” The Spanish Requerimiento of 1513, based on a Papal Bull of 1493 confirming Spanish title to “discovered” lands, declared that the colonizers may “make war against you (Native peoples) in all ways and manners that we can, and shall subject you to the yoke and obedience of the Church; we shall take you and your wives and your children, and shall make slaves of them, and as such shall sell and dispose of them; and we shall take away your goods, and shall do you all the mischief and damage that we can; and we protest that the deaths and losses which shall accrue from this are your fault.”

U.S. history shows similar horrific events, in which Native peoples were the victims of terrible violence at the hands of “Christian Discoverers.” In 1637, the English burned an entire Pequot village, after blocking any escape routes. Captain John Underhill explained the killing of the elderly, women, and children, by saying, “…sometimes the Scripture declareth women and children must perish with their parents…We had sufficient light from the Word of God for our proceedings.”

Across the continent, about 100 years later, Franciscan missionary Junipero Serra was responsible for coercing Native peoples into Christianity, confining them to “missions” where they were forced to labor for the Spanish. Serra justified the practice of whipping Indians who resisted, writing, “That spiritual fathers should punish their sons, the Indians, with blows appears to be as old as the conquest of the Americas; so general in fact that the saints do not seem to be any exception to the rule.” Pope Francis’ intention to canonize Serra during a 2014 visit to the United States has stirred up controversy because of the violence of Serra and the mission system.

The Vatican Congregation of the Holy Office, the church office responsible for these wars of terror still exists, now named The Congregation for the Doctrine of the Faith. Until his election as Pope Benedict XVI, the leader of this Congregation was Joseph Cardinal Ratzinger, known for his efforts to root out “heresies” in the modern church and in literature.

The consequences of Christian domination live on today, most notably in the legal doctrine of “Christian Discovery” in United States property law and federal Indian law (and in parallel laws in Canada, Australia, and New Zealand—all colonial extensions of English Christendom) under which Indians are denied ownership of their lands because they are “heathens.”

The ongoing campaign to remove the doctrine of “Christian Discovery” from U.S. law draws attention to this nasty history. Some Christian churches have joined the effort, calling for an honest reckoning with the historical consequences of Christian terror. It remains to be seen whether Pope Francis will proceed with the beatification of Junipero Serra in the face of increasing public awareness of the historical record.

Pope John Paul II—though he beatified Junipero Serra—acknowledged the violent history of Christianity. He issued more than one hundred apologies for the activities of the Roman Catholic Church over centuries. In March 2000, he issued a sweeping apology for 2,000 years of violence and persecution by the church. As described by one journalist, the Pope “electrified ranks of cardinals and bishops” by “defying warnings from some theologians that the unprecedented apology would undermine the church’s authority.”

One may rightfully find religious history “offensive,” but does that make it offensive to speak about it? Are we to pretend this history didn’t happen?

The government of Turkey provides an example of how far political leaders may go to deny history. Anyone in Turkey who refers to the slaughter of Armenians and Kurds during World War I as “genocide” may be sent to prison for the crime of “denigrating Turkishness.” The “official history” denies the historical record that shows one-third of the Armenian people were wiped out.

Legitimate arguments about history arise from differing views about documents and from discovery of new materials. In the case of Christian violence, Obama’s critics have pointed to no new materials and no differing views of existing documents; their objections arise from political calculations about how (and whether) to look at the acknowledged history.

We may thank Obama for speaking truthfully about religious violence. Nowhere in his remarks did he justify the violence of the Islamic State. Rather, he sought to defuse anti-Muslim anger by reminding us that Christianity also has blood on its hands. Those who criticize his remarks are like those who criticized Pope John Paul II: they are worried more about maintaining their “authority” than about acknowledging truth.

Peter d’Errico graduated from Yale Law School in 1968. He was Staff attorney in Dinebeiina Nahiilna Be Agaditahe Navajo Legal Services, 1968-1970, in Shiprock. He taught Legal Studies at the University of Massachusetts, Amherst, 1970-2002. He is a consulting attorney on indigenous issues.