Militia Dei is a Papal bull

Papal bull

A Papal bull is a particular type of letters patent or charter issued by a Pope of the Catholic Church. It is named after the bulla that was appended to the end in order to authenticate it....

 issued by Pope Eugene III

Pope Eugene III

Pope Blessed Eugene III , born Bernardo da Pisa, was Pope from 1145 to 1153. He was the first Cistercian to become Pope.-Early life:...

 in 1145 that consolidated the Knights Templar

Knights Templar

The Poor Fellow-Soldiers of Christ and of the Temple of Solomon , commonly known as the Knights Templar, the Order of the Temple or simply as Templars, were among the most famous of the Western Christian military orders...

's independence of the local clerical hierarchy by giving the Order the right to take tithes and burial fees and to bury their dead in their own cemeteries. The Knights were allowed to travel through Europe freely.

This bull together with Omne Datum Optimum

Omne Datum Optimum

Omne Datum Optimum was a Papal Bull issued by Pope Innocent II in 1139 that initially endorsed the Order of the Poor Knights of Christ and of the Temple of Solomon , in which the Templar Rule was officially approved, and papal protection given...

(1139) and Milites Templi

Milites Templi

Milites Templi is a papal bull issued by Pope Celestine II in 1144 that ordered the clergy to protect the Knights Templar and encouraged the faithful to contribute to their cause...

form the foundation for the Order's future wealth and success.