Guardian angel

A guardian angel is a spirit who is believed to protect and to guide a particular person. The concept of tutelary angels and their hierarchy was extensively developed by Pseudo-Dionysius the Areopagite, in the 5th c. CE

The English physician and philosopher Sir Thomas Browne (1605-82) wrote:

Therefore for Spirits I am so farre from denying their existence, that I could easily beeleve, that not onley whole Countries, but particular persons have their Tutelary, and Guardian Angels: It is not a new opinion of the Church of Rome, but an old one of Pythagoras and Plato; there is no heresie in it, and if not manifestly defined in Scripiture, yet is it an opinion of a good and wholesome use in the course and actions of a man's life, and would serve as an Hypothesis to salve many doubts, whereof common philosophy affordeth no solution.

from Religio Medici part 1 paragraph 33

The Religion of a Physician or Religio Medici was placed upon the Papal index in 1645 as forbidden reading for Catholics.