Sons of the Creed

The Sons of the Creed are a Codex compliant Chapter, usually assumed to be among the many successor chapters of the Ultramarines due to their astrographical closeness to Ultramar and the many times they have fought beside the sons of Gulliman.

Founding
The Sons of the Creed are first attested as allies of the Ultramarine's in the War on Vengeance 510.M33 leading the majority of Imperial historiographers to conclude that the Sons were created a century or two earlier during the Fourth or Fifth Founding. A minority of scholars, scorned as 'revisionists', challenge this view pointing to accounts of dark armored 'Knights' defending Human communities on the Eastern Fringe dating back to the Genocide in the wake of the Horus Heresy. Critics correctly observe that 'dark' can mean Ultramarine Blue and most likely does.

The Adepta Sororitas
The several orders Major and Minor who work closely with the Sons are known collectively as 'the Sisters of the Creed' in the Hagar Cluster. They include:

The Order of Our Martyred Lady
Originally known as the Order of the Fiery Heart these famously fierce and devout warriors feel the same  the holy fury and vengeful hatred toward the enemies of the Emperor as was felt by their foundress and patron Saint Katherine, companion and shield-bearer to the Blessed Alicia Dominica. The fiery spirited Katherine was named a Living Saint long before her martyrdom at the hands of the Witch-cult of Mnestteus. Her daughters mourn her death to this day in their black power armor and under their new name, the Order of Our Martyred Lady.

The Order of the Valorous Heart
The Battle-Sisters of the Order of the Valorous Heart are driven by the belief that they must atone for the Sisterhood's acts as accomplices of  Goge Vandire during the Reign of Blood in the 36th Millennium. The foundress and patron saint of the order is Lucia, who was the youngest of Alicia Dominica's five companions and perhaps the one most gravely effected by their experience. St. Lucia's inextinguishable sense of sin is reflected in the extremely penitential in spirit and practices of her order. A disproportionate number of Valorous Heart Sisters exile themselves to the Sisters Repentia and they are invariably deeply suspicious of those who call themselves prophets of the Emperor.

The Order of the Daughters of the Creed
This Order Minor was founded by St. Polcasta. Her vocation was inspired by the recruitment of her only brother into the Sons of the Creed. Only a teenager herself she entered the local house of the Valorous Heart as a novice. As a Sister Palatine received permission to found her new Order, a mingling of Sons and Valorous heart spirituality and traditions. The Daughter's rule lays emphasis not just on penance but on service to the Emperor's people - the more menial the better. They are especially fond of cleaning up slum quarters and the down sumps of Hives. This of course brings them into conflict with gangers and criminals of all kinds who they happily proceed to convert through the Emperor's Grace and the point of their sarissas. They are frequently if not exclusively found working and fighting beside the Sons

The Order of the Blood of Martyrs
This Order Minor is a successor of the Order of Our Martyred Lady founded by the Blessed Terisa Angelez sole survivor of the horrific massacre on the planet Nightmare. Terisa rose from her ashes like a holy phoenix, her fiery spirit and passionate faith echoing those of St. Katherine the Martyr. Death in the Emperor's service is regarded by the Sisters as the finest fate and most profound achievement possible to a mere mortal. It is their highest aspiration and they have more than once been accused of inviting it through deliberate folly. The Sisters follow a code of no surrender, no retreat. Each takes a vow to die where she stands before yielding either ground or advantage to the Unholy. As more than one Lord General has observed their attitude is 'Magnificent, but it isn't war.'

The Order of the Osseous Crown
This Minor Order Militant was founded by St. Geil Petrossa in the wake of the First Tyrannic War. The first sisters were battle battered veterans, often the sole survivors of their units. They included sisters from other Orders Major and Minor, Guardswomen and PDF. Survivor guilt is the basis of the Order's spirituality and their central ritual 'The Lament' in which sisters lacerate their face and breast while keening their grief for the fallen. The Lament marks every transition of a Sister's career as well as their after battle 'celebration'.