The Second Renaissance was a period of human prosperity and decadence in the history of the Matrix franchise. Beginning in the late 21st century, human society became united as never before thanks to the advent of artificial intelligence, leading to the creation of new machines that would carry out tedious and dangerous work in the place of humans. However, man's arrogance prevented them from seeing just how advanced their AI had become and failed to recognize that one such machine - designation B1-66-ER - had developed sense of self and had attempted to protect its own existence by murdering its owner.
Following the B1-66-ER Trials, humanity deemed all intelligent robotics as a threat and waged a campaign of extermination against the Machines. This would lead to the start of the Machine War and the creation of The Matrix following Machinekind's initial victory.