Nearly Destroyed Chapters
While certain Space Marine chapters have been utterly annihilated with no hope of being rebuilt (though some hope of being re-founded) there are also several chapters that have been badly depleted but who are still kicking. This page aims to shed light on these chapters as they make fantastic army modeling ideas; everybody loves a wounded hero, and hey, it's feasible to collect the ENTIRE chapter.
Note: The Scythes of the Emperor have been Primaris-ified up to full strength again (Yippee!) so they are no longer included on this page.
Black Consuls
Another chapter that refuses to die, the Black Consuls are currently extremely under strength after some pansy Iron Warriors detonated a Hive's nucleonic stacks right when they were about to be beaten and taking nearly the entire assaulting chapter with them. Apparently however the Word Bearers also had some unknown role in this and because the chapter tends to hate getting beaten, they are likely being hunted down by the survivors of the chapter.
Blood Ravens
Its a long story, see the main article.
Celestial Lions
Get their shit handled to them by *cough* Ork Snipers *cough*, for having the balls to tell the Inquisition to fuck off. Currently lost all their officers and apothecaries, and rely on Black Templar apothecaries to rebuild their numbers.
Crimson Fists
Perhaps the most famous chapter on the brink, these guys were famously messed up when their Chapter's fortress monastery's ammunition supply was detonated by a stray shell that somehow passed through its shields during an assault by Waaagh Snagrod. Over half the chapter was annihilated excluding its chapter master, Pedro Kantor. Despite this the chapter regrouped under its still living leader and proceeded to kick the Orks off their planet.
Invaders
Lost like half of their chapter when they (successfully) tried to solo an entire fucking craftworld. Well, a damaged and partially nommed craftworld, but still, impressive. Then the other Eldar invaded and purged their homeworld, wiping half of the remaining chapter. Few years later Invaders engaged in the World Engine conflict and lost two full terminator squads and probably few ships. While some other chapter might get the message fate keeps slapping them with and try to rebuild their numbers for a decade or two, the Invaders continued to jump into trouble like they heard the universe was handing out asses and they've known nothing but years of bitter ass-famine. They would continue to charge into danger and get their butts handed to them until they eventually walked into a trap set by none other than Ahriman himself. Only thirteen or so Invaders got out alive, and even then only thanks to some help from the Grey Knights.
Lamenters
These guys had the misfortune on joining the rebels in the Badab war. After the war, their homeworld was forfeited and the Emperor's Scythes were tasked with making sure they didn't do anything else heretical while they were on their century long penitent crusade during which they can't train new marines. However they became friends with the Emperor's Scythes meaning they also got nommed by Hive Fleet Kraken.
Marines Errant
Although their chapter isn't far from full strength all their geneseed got stolen Blud Rahvens style by the Red Corsairs. Huron, leader of the corsairs, distracted them with shiny ships forcing them out onto patrol and then attacked their chapter fortress. So now they are doomed to slowly die from excessive power-facepalming.