Dark Night of the Soul

Hi everyone. I read a good book on intercessory prayer recently and the author mentions a period that is documented by a lot of historical preachers/evangelists called The Dark Night of the Soul. I googled the term but was overwhelmed with all the varying results that came up, some of which had nothing to do with Christianity at all.
So I thought I would ask the question here and see what you all can tell me about this. What is it supposed to mean and who wrote about it?

Thanks!

The "dark night of the soul" refers to a time
when GOD seems to hide Himself and the heavens
seem to be closed to our prayers. The LORD is
trying to school us to persevere and prevail in
prayer. The book is by John Chrysotom; also
known as ST. John of the cross.