819.M41 A percieved slight causes the Mortifactors and Crimson Fists to come to blows. Only a personal interessionby Marneus Calgar ends the dispute before it escalates to open war. The matter is kept from the attention of the Adeptus Terra.
934.M41 The Toran VI Massacres. The Crimson Fists defeat the warband of Chaos Lord Sathash the Golden
989.M41 Waagh! Snagrod rampages across the Loki sector, culminating in a devastating assault on Rynns World. The Crimson Fists chapter is left battered and bloodied, but determined to rebuild.
Current year is 999.M41
Kantor has been Chapter Master for just under 100 years, so 899.m41~ (roughly)
Service record goes back 250 years, so 749.m41~ is his induction (roughly)
Codex Space Marines (2008)