The annual World Watch List published by Open Doors, which provides a global overview of anti-Christian persecution during the year under consideration, and country-by-country accounts of places where Christians face the gravest danger.

Aid to the Church in Need, a widely respected Catholic relief organization based in Germany, which also publishes occasional reviews of anti-Christian persecution, including detailed incident reports from a variety of different countries.

Fides, the Vaticans missionary news agency, which publishes an annual report on Catholic pastoral workers killed around the world during the previous year, including bishops, priests, brothers, deacons, nuns, and laywomen and -men who worked professionally for the Catholic Church.

Asia News, another Catholic news agency sponsored by the Pontifical Institute for Foreign Missions and directed by Fr. Bernardo Cervellera, a dynamic Italian who, among other things, is one of the best Sinologists in the Catholic world. In my experience, Asia News probably does the best job, day in and day out, of documenting cases of anti-Christian persecution in the developing world, not just of Catholics but of all stripes of Christians.

Forum 18, a Norwegian human rights organization that promotes religious freedom, and which is especially adept at monitoring the situation in the former Soviet sphere. Its regular news bulletins and analyses are extremely useful for understanding whats happening in that part of the world.

Nina Shea, Paul Marshall, and others at the Hudson Institute, who have done yeomans work over the last two decades to bring the issue of anti-Christian persecution to the forefront of American consciousness, and who continue to provide regular dispatches and overviews.

The Pew Forum on Religion and Public Life in Washington, D.C., which provides the most reliable hard data on religious harassment and persecution around the world.

The Center for the Study of Global Christianity at Gordon-Conwell Theological Seminary in South Hamilton, Massachusetts, which has pioneered the statistical investigation of Christian martyrdom and remains the lone serious source for estimates of the number of contemporary martyrs.

The Catholic Near East Welfare Association (CNEWA), which has almost a century of experience delivering humanitarian and pastoral support to the churches of the Middle East, assisting not just Catholics but people of all faiths, and whose personnel often know the lay of the land better than anyone.

Francesca Paci, a veteran print and broadcast journalist in Italy, whose 2011 book Dove muoiono i Cristiani (Where Christians are dying), published by Mondadori, was so good that I almost decided not to write this one. Communications 101, however, teaches us that sometimes the key to getting a point across is repetition. I hope this book accomplishes in English some of what Paci achieved in Italian.

Obviously, any misrepresentation or inaccuracies in the presentation of the incidents described in these pages is my fault alone and shouldnt be attributed to any of the organizations or individuals listed above.

Looking back, its often hard to know exactly where the inspiration for a book came from, but I can date with precision the first time I considered global anti-Christian persecution as a possible topic. It was during a 2009 conversation with Cardinal Timothy Dolan of New York, who mused that perhaps Christians havent roused themselves to confront the problem because we dont have our own Holocaust literature. He meant that Christians havent told the stories of their new martyrs in a compelling way, in the same fashion that Jewish authors have described the horrors of the Shoah. This book is my own small contribution to a budding Christian genre dedicated to telling these stories, and I want to thank Cardinal Dolan for that nudge.

Id like to take this chance to express gratitude to the team at Image, including Gary Jansen, Johanna Inwood, Carrie Freimuth, and their colleagues. As Ive had the opportunity to say to them personally, they are the best, the very best, and this book would not exist without their support. As always with my book projects, thanks also go to the editorial team at the National Catholic Reporter for tolerating both my growing obsession with the subject of anti-Christian persecution and my occasional absences to produce the manuscript.

Finally, the most profound thanks go to my wife, Shannon, and our beloved pug, Ellis, without whom well, theyre my sine quo nihil without whom, nothing.