Many people trace the beginning of modern hypnosis back to Milton Erickson.  He was master of indirect subtle hypnosis and moved the whole field of hypnotherapy probably up one level when it comes

Not only did he write many books about hypnotherapy, many  books were also written about him and his approaches and contribution.  Challenged by severe medical conditions throughout his own life, he was able to overcome them where possible through self-hypnosis. 

 
His history of pain and suffering  (mainly being struck with polio two times and being on a wheelchair later) also granted him a unique perspective and hardly-learned abilities, something that you can't learn in the hypnotherapy class. 

 
Erickson was mainly a hypnotherapist, and was brought up for using hypnotherapy in his psychotherapeutical practice.  

 The core of his approach was to operate from the level and perspective of his patients. unlike most other therapists who were and are busy installing their own world and their own beliefs into their client's life.

The work of Milton H. Ericksson, MD,  formed a basis for modern hypnotherapy, as well as neurolinguistic programming and many other modern self-help and psychotherapy approaches.