Well, I'm not really interested in the life history of the man, but rather what kind of person he was. I encountered his name in a book that I've finally gotten around to read, quote:
"[...] John of Salisbury, attacked the Roman imperial cult as the work of impious flatterers which promoted despotism." (Price, 1984)
Since I've never even heard of the man I don't know what to take from this statement. Is he seen as a man who affected politics in his time? Was he a powerful man? Looking at the statement itself I assume he was a Christian, but was he the "hardcore" kind who thought that every non-Christian should suffer forever in hell for their sins; or the lighter kind who might have been okay with deviations in belief? He is obviously writing for his own era, but he could still have been writing truthfully or provocatively and I'm interested in learning which one it is.
This would be much easier to answer if there were better documentation of his life. All that can be understood is that John of Salisbury was a very religious man, and his work concerning the ethics of royalty is essentially a condemnation.
To further the anti-royal, pro-religion theory, he was understudy to Thomas Becket, famously murdered in unwitting service of the King. Much of his work focuses on reducing suffering and simplifying life from what was unholy. On top of that, after leaving England, he was appointed Bishop of Chartres, so it's reasonable to presume he was pious in his intentions.