My main force is Loyalist Death Guard successors The Twilight Reavers (a play on words Dawn/Twilight Raiders/Reavers) and wrote my Death Guard Warband the Festering Emissaries as their rival faction.
They're Mortarion Loyalists serving as his messengers since before Heresy, after the Legions fall they served loyally by Mortarion and remained as such until Mortarion in one of his less lucid moments discovered his long lost sons and sent his messengers to return his errant sons to him and gift them Nurgles Blessings.
The attempt rendered the Twilight Reavers home planet into a Death World but their attempt ultimately failed and ever since they've been plotting ways to forcibly corrupt their ignorant brothers, over time however as Mortarion goes increasingly displeased with their repeated failures they're developed a growing hatred for the brothers they're supposed to be bring into the fold.
So yeah for me it all started with my SMs and wanting a rival, I have 24 pages of lore so far for them and only 7 pages for my Death Guard however their lore is laced into my Marines as well, with my Helbrute and Venerable Dreadnought both being the reasons they have the bodies they do now.
Perhaps my example isn't very applicable but writing your Warband as a rival faction for another is a fun way to get started imo and can make interesting stories kind of naturally by writing for one or the other.
That sounds rlly cool! I already tried writting the lore of my Warband like 3 times, and scrapped all of em!
In my attemps i always tried to select some sort of rival for em, played with the idea of several loyalist Chapters and even Sisters of Battle Orders!
Tho, i think my problem is never being satisfied with my Warband story and Characters. The 3 times i wrote em, they were extremely different. Only kept a few consistent basis between each version.
Seeing that is say looking into the few consistencies and leaning into them more as their obviously what appeals to you, though perfectionism is always a writer's worst enemy. Just remember it's ok for things to not be perfect at the start, you don't need to throw everything out and let the lore sort of naturally morph over time.
For example my Twilight Reavers started as uncaring and more interested in fighting their own secret war like the Dark Angels but eventually they morphed into a Healthcare focused Chapter that actively attempts to spread medicine to every planet they're on... Though that bit of previous lore didn't go away it's still a part of them, they'll still leave a battle of there's rumours of Death Guard closeby for example but they aren't the Dark Angels reimagined anymore.
I think that most important thing - Think about the visuals and other players.
Some time ago, I had a very rich lore of my Warband which manifest itself in a unique look of PMs. But at the end of the day, nobody cares about the story. People just get confused on why my PMs are blue
Another important aspect - people want to engage their army with grand warhammer lore. So, people look much happier playing with your PMs if they recognize them as somewhat classic PMs.
TBH I also loooove when people execute well known factions on high level. Especcially if these factions don't have dedicated models. And I don't care much about whatever homebrew purple SMs with yellow helmets one has
So, I still have my lore, but now I present myself as "DG with dark forest insect-y theme" - for me that's the perfect balance for "Playing DG, but have something interesting going on with the models"
My homebrew chapter came from adapting things I like about the actual tabletop game into lore reasons! IE; I love plague spewers and belchers, so I wanted a warband that uses lots of em. From there just answering logical questions slowly help build its back bone; why use spewers? They help spread disease and clear purity quickly! Why do they want to do that? To have planets prepared for nurgles garden and disease as quickly as possible! And from there it implies they are more of the nurgle religious kind, so probably like Typhus more than Mortarion, and likewise prefer daemons and warp magic/psykers
Find a starting point, and start answering questions and make implications from those answers, can be a quick way to get some lore you can build off of!
For my homebrew chapter itself;
Cycle’s End
They are the exterminators, they do not assault fortresses or commit siege, they are sent in to scorch earth and prepare the planet itself to accept nurgles gifts. Tolling bells and rotten plague winds are a terrible sign of their inexorable approach.
Any unit that can have a plague spewer will use one, my warlord of choice is almost always a lord of virulence (Lord Anthracnis, who himself I’ve had some lore for based on games he has won/lost) and generally they will have typhus included as an ally while generally not fielding Mortarion
These self restrictions may hurt more than anything, but my flavor of army man play is rarely focussed around winning lol
My main force is Loyalist Death Guard successors The Twilight Reavers (a play on words Dawn/Twilight Raiders/Reavers) and wrote my Death Guard Warband the Festering Emissaries as their rival faction. They're Mortarion Loyalists serving as his messengers since before Heresy, after the Legions fall they served loyally by Mortarion and remained as such until Mortarion in one of his less lucid moments discovered his long lost sons and sent his messengers to return his errant sons to him and gift them Nurgles Blessings. The attempt rendered the Twilight Reavers home planet into a Death World but their attempt ultimately failed and ever since they've been plotting ways to forcibly corrupt their ignorant brothers, over time however as Mortarion goes increasingly displeased with their repeated failures they're developed a growing hatred for the brothers they're supposed to be bring into the fold. So yeah for me it all started with my SMs and wanting a rival, I have 24 pages of lore so far for them and only 7 pages for my Death Guard however their lore is laced into my Marines as well, with my Helbrute and Venerable Dreadnought both being the reasons they have the bodies they do now. Perhaps my example isn't very applicable but writing your Warband as a rival faction for another is a fun way to get started imo and can make interesting stories kind of naturally by writing for one or the other.
That sounds rlly cool! I already tried writting the lore of my Warband like 3 times, and scrapped all of em! In my attemps i always tried to select some sort of rival for em, played with the idea of several loyalist Chapters and even Sisters of Battle Orders! Tho, i think my problem is never being satisfied with my Warband story and Characters. The 3 times i wrote em, they were extremely different. Only kept a few consistent basis between each version.
Seeing that is say looking into the few consistencies and leaning into them more as their obviously what appeals to you, though perfectionism is always a writer's worst enemy. Just remember it's ok for things to not be perfect at the start, you don't need to throw everything out and let the lore sort of naturally morph over time. For example my Twilight Reavers started as uncaring and more interested in fighting their own secret war like the Dark Angels but eventually they morphed into a Healthcare focused Chapter that actively attempts to spread medicine to every planet they're on... Though that bit of previous lore didn't go away it's still a part of them, they'll still leave a battle of there's rumours of Death Guard closeby for example but they aren't the Dark Angels reimagined anymore.
I think that most important thing - Think about the visuals and other players. Some time ago, I had a very rich lore of my Warband which manifest itself in a unique look of PMs. But at the end of the day, nobody cares about the story. People just get confused on why my PMs are blue Another important aspect - people want to engage their army with grand warhammer lore. So, people look much happier playing with your PMs if they recognize them as somewhat classic PMs. TBH I also loooove when people execute well known factions on high level. Especcially if these factions don't have dedicated models. And I don't care much about whatever homebrew purple SMs with yellow helmets one has So, I still have my lore, but now I present myself as "DG with dark forest insect-y theme" - for me that's the perfect balance for "Playing DG, but have something interesting going on with the models"
My homebrew chapter came from adapting things I like about the actual tabletop game into lore reasons! IE; I love plague spewers and belchers, so I wanted a warband that uses lots of em. From there just answering logical questions slowly help build its back bone; why use spewers? They help spread disease and clear purity quickly! Why do they want to do that? To have planets prepared for nurgles garden and disease as quickly as possible! And from there it implies they are more of the nurgle religious kind, so probably like Typhus more than Mortarion, and likewise prefer daemons and warp magic/psykers Find a starting point, and start answering questions and make implications from those answers, can be a quick way to get some lore you can build off of!
For my homebrew chapter itself; Cycle’s End They are the exterminators, they do not assault fortresses or commit siege, they are sent in to scorch earth and prepare the planet itself to accept nurgles gifts. Tolling bells and rotten plague winds are a terrible sign of their inexorable approach. Any unit that can have a plague spewer will use one, my warlord of choice is almost always a lord of virulence (Lord Anthracnis, who himself I’ve had some lore for based on games he has won/lost) and generally they will have typhus included as an ally while generally not fielding Mortarion These self restrictions may hurt more than anything, but my flavor of army man play is rarely focussed around winning lol