What is the history of laws against cruel and unusual punishment?

In addition to prohibiting excessive bail or fines, the Eighth Amendment to the US Constitution prohibits cruel and unusual punishment. It was ratified in 1791, but the idea of prohibiting unjust consequences can be traced all the way back to 1689 to the English Bill of Rights, which also forbade cruel and unusual punishment. George Mason included a similar law in Virginia's Declaration of Rights in 1776 as well.
What, exactly, "cruel and unusual" means is based on the amount of pain, suffering, and/or humiliation that the recipient might be subjected to. In 1972, the United States Supreme Court case Furman v. Georgia refined that definition further, establishing a set of principles that can be used to discern whether a proposed consequence is "cruel and unusual." According to these guidelines, a punishment cannot:
Degrade one's humanity
Be arbitrary
Be something that is clearly rejected by society's sense of justice
Be less effective than a less severe form of punishment
Clearly, there's overlap between these principles, and that is intentional. The underlying goal set forth by Justice William Brennan in his Furman v. Georgia opinion was to set a precedent for punishment that preserves human dignity. To that end, he made it clear that he expected individual states to not create laws that violate these four principles.
https://constitutioncenter.org/interactive-constitution/amendment/amendment-viii