The Order of the Blessed Virgin Mary of Mercy is an international community of priests and brothers who live a life of prayer and communal fraternity. In addition to the vows of poverty, chastity and obedience, their members take a special fourth vow to give up their own selves for others whose faith is in danger.
The Order, also called the Mercedarians, or Order of Mercy, was founded in 1218 in Spain by St. Peter Nolasco to redeem Christian captives from their Muslim captors. The Order exists today in 17 countries, including Spain, Italy, Brazil, India, and the United States. In the U.S., its student house is in Philadelphia, and it also has houses in New York, Florida, and Ohio.
Today, friars of the Order of Mercy continue to rescue others from modern types of captivity, such as social, political, and psychological forms. They work in jails, marginal neighborhoods, among addicts, and in hospitals. In the United States, the Order of Mercy gives special emphasis to educational and parish work.
The spiritual and communal life of the friars include prayer, meditation, Holy Mass, recreation, and apostolate. Their life is based on the Rule of St. Augustine and the Constitutions of the Order (PDF).
Overall, the Order of Mercy commits itself to give testimony to the same Good News of love and redemption that it has shown since the beginning of its history.
See also the Order of Mercy Wikipedia entry.