This is how much money Alfred Nobel left to fund the eponymous prize

Alfred Nobel made his fortune primarily from three inventions, all in the field of explosives. 

He invented the mercury fulminate blasting cap, a mechanism for detonating nitroglycerine. 

The Nobel Prize: The good, the bad and the ugly

He also invented dynamite, which is a mixture of nitroglycerine and diatomaceous earth, a type of silica and solid material that decreases the shock sensitivity of nitroglycerine, thereby safely harnessing the energy of nitroglycerine, allowing it to be safely transported and enabling it to be triggered into an explosion only by means of a blasting cap.

And the third invention by the Swedish scientist was gelignite, another nitroglycerine-based mixture, which is more stable than dynamite, burning slowly and unable to explode without a detonator, as well as being one of the cheapest explosives.

Nobel idealistically thought that his disruptive innovations would be used for the benefit of humankind. He purportedly loathed war his entire life. Nobel said that he dreamed of creating a substance of "such frightful efficacy for wholesale destruction that it would make wars impossible." 

During his own lifetime, mistaken information caused a newspaper to prematurely issue an obituary of him. It described him as "merchant of death," much to his dismay. 

The shocking experience of seeing how his contributions were apparently perceived motivated Nobel to dedicate much of his fortune, through his last will and testament, for the start of the Nobel Prize project, intended to reward and advance human progress across several fields.

Nobel wrote his last will and testament on 27 November 1895, about a year before his death. In it, he stipulated that most of his estate, which was worth more than SEK31 million (adjusted to the value of today's currency, approximately SEK1.794 billion or over $160 million), was to be converted into a fund and invested in "safe securities." 

The income generated by these investments was to be "distributed annually in the form of prizes to those who during the preceding year conferred the greatest benefit to humankind."