Saint Sabbat
"That which was will be.That which dieth will live. That which falleth will rise up. This, I say to you, is the nature of things, if you but once believe."
- – Saint Sabbat
"Sabbat Martyr"
- – a phrase spoken in reference to the Saint
Saint Sabbat, AKA "The Beati" is an Imperial Saint from M.35 and has been a prominent figure in the Gaunt's ghosts Series. She was described as a small, beautiful woman, with green eyes and short dark hair. In the Gaunt's Ghosts series she is said to have some connection with the Sister of Battle Order, Order of the Martyred lady, which in the books says she was their founder. But she was born, crusaded, and died all before the Age of Apostasy even happened, and that the actual Founder of the Martyred lady was Saint Katherine, meaning she could not be connected to them in that way, but she did apparently have an small militant force of what seem to be Proto-sisters that crusaded with her. With the 8th edition Sister Codex, the Connection to the Martyred lady has been retconned to a connection to the original Daughters of the Emperor. This makes much more sense and probably means after her Crusade her Proto-sisters left the Sabbat Worlds and became the Daughters of the Emperor who later on would become the Sisters of Battle.
Life and Martyrdom
Sabbat was born on the Agri/feudal world of Hagia where she was but a simple Shepard girl in her youth. However Hagia and the worlds around had a very chaotic problem, mainly Chaos. She apparently walked down from the hills and felt Big E himself talking to her, and considering what she did next he probably said something along the lines of "HEY, GO CRUSADE, IT'S GREAT". So with the Emperor's light guiding her, she built up an army and led a planetary crusade to wipe chaos, and multiple Xenos species off the planet. Afterwards she went on, what can only be described as a crusade high. She lead multiple Imperial forces into the near by sector and began to conquer all the planets in the name of the Emperor.
She was so successful that she caught the attention of multiple Space Marine Chapters to come help her and the crusade and brought in many experienced and loyal Imperial personnel. After 105 years of spreading the Imperium's reach to the sector and making it a viable Imperial region in space, She finally fell fighting on Harkalon, where she suffered "9 holy wounds". She was was entombed upon Hagia and made an Imperial Saint. The region of space she had conquered was named the "Sabbat Worlds" in her honor and the rest, is history.
It's just a shame the Imperium never learns from it.
The Sabbat's World Crusade and Resurrection
Speed forward to M.41 and all the shit has hit the fan again. Most of the Sabbat Worlds had fallen to the Ruinous powers... again, so the Imperium finally decided to stop acting like an obese whale stuck on a hill and sort it out. The Sabbat Worlds Crusade was launched by the High lords of Terra under Warmaster Slaydo (later Warmaster Macaroth) to recapture the sector. After her tomb was personally defended by the Tanith First, she was resurrected but not really, but also kinda, and then she actually was.
Okay, let me explain, and listen because it gets confusing, The woman claiming to be Sabbat resurrected was just a delusional woman who, upon being reviewed by Colonel-Commissar Ibram Gaunt and a Haigan priest showed, she wasn't the Saint but they acted like she was so the Crusade morale would be kept up. However the "false Sabbat" did do some things the actual Saint wanted to happen, that being asking for the Tanith First to come protect her and publicly announce her arrival on some back water planet so all the chaos forces in the area would come and try and kill her (it was part of a plan) so the real Sabbat might have been influencing her in some way. However at the same time some random Pilgrim girl is hinted to be the actual Saint Reincarnated, but she then dies, and then Sabbat actually resurrects herself in the "false Sabbat's" body, and this time she actually is Saint Sabbat Reincarnated.
TL/DR; Saint Sabbat Indeed does become Reincarnated and goes on to pull off a pretty genius tactical move and save the Sabbat Worlds crusade, from collapsing. After which goes on to help lead the Crusade from the Front line with the Warmaster.
The newly Resurrected Saint Sabbat is also a bit of a combat monster with her pulling off stuff like murdering a Fucking Baneblade all on her own, and fighting a Chaos Marine Champion while being surrounded by him and his personal guard and still killing him an taking his head. Suffice to say, she's pretty badass now.
Playing Sabbat in Game
It's fairly safe to say that "The Beati" won't get herself a model, despite being one of the most popular Saints in 40k Lore (no small part in thanks to the Gaunt's Ghosts Series), so if you want to play her on table top your best bet would be to convert Saint Celestine's model and use her rules (come on GW, no generic living saint rules?)