Al Ghazali ,Abu Hamid Mohanned Ibn Mohammed was born in 1050 and died in 1111. He was a great philosopher writers of numerous books and a great teacher of Islam. He had a great influence om Rumi and many other big names of Islam.
Here is a link to a short and very informative Interview (in 2011) of Professor Frank Griffel of Yale University talking about his book on Al Ghazali. https://www.youtube.com/watch?v=cY-u_37SNz4 .