Overview
Envoy's are an ambiguous class of "super solders" who were created alongside the technology of the Human Race hundreds of years before the plot of the TV show. They worked well with the technology that was advanced over time, specifically the Cortical Stack and the consequential ability to Needlecast to off-world destinations. They are good fighters and could make full use of movement between sleeves for combat as they don't experience Sleeve Sickness -which is the period of disorientation that someone feels after their stack is placed in another sleeve. Their ability is undisputed and this is exemplified when Laurens Bancroft meets with Takeshi Kovacs for the first time, with Bancroft stating "There are very few of us now who saw first-hand what the Envoys could do."
History
There is no specific timeline of events, but nearly all the Envoys have been killed, with <a data-rte-meta="%7B%22type%22%3A%22internal%22%2C%22text%22%3A%22Takeshi%20Kovacs%20%28TV%29%22%2C%22link%22%3A%22Takeshi%20Kovacs%20%28TV%29%22%2C%22wasblank%22%3Atrue%2C%22noforce%22%3Atrue%2C%22wikitext%22%3A%22%5B%5BTakeshi%20Kovacs%20%28TV%29%5D%5D%22%7D" data-rte-instance="1659097-8692529595a8c46b11f7e0" href="/wiki/Takeshi_Kovacs_(TV)" title="Takeshi Kovacs (TV)">Takeshi Kovacs (TV)</a> and his sister <a data-rte-meta="%7B%22type%22%3A%22internal%22%2C%22text%22%3A%22Reileen%20Kawahara%20%28TV%29%22%2C%22link%22%3A%22Reileen%20Kawahara%20%28TV%29%22%2C%22wasblank%22%3Atrue%2C%22noforce%22%3Atrue%2C%22wikitext%22%3A%22%5B%5BReileen%20Kawahara%20%28TV%29%5D%5D%22%7D" data-rte-instance="1659097-8692529595a8c46b11f7e0" href="/wiki/Reileen_Kawahara_(TV)" title="Reileen Kawahara (TV)">Reileen Kawahara (TV)</a> being the only known remaining Envoys. They were hunted and killed by the <a data-rte-meta="%7B%22type%22%3A%22internal%22%2C%22text%22%3A%22United%20Nations%22%2C%22link%22%3A%22United%20Nations%22%2C%22wasblank%22%3Atrue%2C%22noforce%22%3Atrue%2C%22wikitext%22%3A%22%5B%5BUnited%20Nations%5D%5D%22%7D" data-rte-instance="1659097-8692529595a8c46b11f7e0" href="/wiki/United_Nations" title="United Nations">United Nations</a>' military forces for allegedly rebelling against the government of the day, which ruled over all known human settlements.
Public Opinion
The modern perception of the Envoys is that they are an extinct terrorist group who sought to undermine the power of the United Nations and were rightly killed off. This perception meets the official narrative that children are taught in Schools with Envoys being treated wholly as 'bad guys' who were rightly killed for their crimes. This false narrative is discovered by Kovacs when he stumbles upon an exhibition that glorifies the execution of the Envoys by <a data-rte-meta="%7B%22type%22%3A%22internal%22%2C%22text%22%3A%22Colonial%20Tactical%20Assault%20Corps%20%28TV%29%22%2C%22link%22%3A%22Colonial%20Tactical%20Assault%20Corps%20%28TV%29%22%2C%22wasblank%22%3Atrue%2C%22noforce%22%3Atrue%2C%22wikitext%22%3A%22%5B%5BColonial%20Tactical%20Assault%20Corps%20%28TV%29%5D%5D%22%7D" data-rte-instance="1659097-8692529595a8c46b11f7e0" href="/wiki/Colonial_Tactical_Assault_Corps_(TV)" title="Colonial Tactical Assault Corps (TV)">Colonial Tactical Assault Corps (TV)</a> (CTAC) -which is being visited by a group of school children at the time.