The great dragonmarked families are the barons of industry and commerce throughout Khorvaire and beyond. Their influence transcends political boundaries, and they remained mostly neutral during the Last War. While not technically citizens of any nation, the matriarchs and patriarchs of each house live in splendor within their enclaves and emporiums located throughout Khorvaire. These dynastic houses of commerce derive their power from the dragonmarks — unique, hereditary arcane sigils that manifest on certain individuals within the family, granting them limited but very useful magical abilities associated with the trade guilds the family controls.
The thirteen dragonmarked houses constitute an aristocracy of commerce and industry across Khorvaire. The blood members of each family have wealth and social status that puts them firmly in the middle to upper classes of Khorvairian society. The house nobles and their immediate relatives share the highest status in the land, equivalent to the royal houses and the highest-ranking clergy. Scions further removed from the main bloodline share and take advantage of this status as the nobles allow, but on their own they rank in the middle class.
Individual dragonmarks appeared within bloodlines, and soon family dynasties sprang up to take advantage of the dragonmark powers. Each family created an economic empire using the dragonmarks, and the dragonmarked houses developed into independent commerce states operating across multiple nations. The War of the Mark, which ended about fifteen hundred years ago, stabilized the houses and ended the threat of aberrant and mixed marks that might have destroyed the economy of Khorvaire. Today, twelve dragonmarks shared among thirteen houses form the basis for economic power across the continent.
Agreements reached at the end of the War of the Mark formalized tenets and traditions that all the houses adhere to. These include rules concerning neutrality (all houses make a show of remaining neutral so that they can operate in all nations), fair trade and practices, family naming conventions, and a ban on marriages between houses so that the dragonmarks remain pure.
There are fourteen dragonmark marks, though the Mark of Death, possessed by House Vol, is extinct. For the longest time, there were only thirteen until last year when a group possessing aberrant marks were somehow changed into a legitimate dragonmark line. The Mark of Shadow is possessed by two separate Houses, Phiarlan and Thuranni.
- House Cannith: House Cannith is the dragonmarked house of humans who carry the Mark of Making in their bloodlines. It is among the leaders of the dragonmarked houses, and the greatest artifice of modern Khorvaire is of Cannith design.
- House Deneith: House Deneith is the dragonmarked house of humans whose members are highly-acclaimed mercenaries and bodyguards known for their efficiency and martial skill.
- House Ghallanda: House Ghallanda is a dragonmarked house of halflings found throughout Khorvaire. Ghallanda is one of the few dragonmarked houses that are not involved with some form of arms dealing or soldiering. Instead members of House Ghallanda are Khorvaire's best hosts dealing in food and shelter.
- House Jorasco: House Jorasco is a dragonmarked house of halflings found throughout Khorvaire. Their house enclave is located in Karrnath, though the mark originated among the nomadic tribes on the Talenta Plains.
- House Kundarak: House Kundarak is the dragonmarked house of dwarves with services focused in security and banking. Their primary customers are those who have enough coin to buy something worth protecting, including the wealthy, the powerful, other dragonmarked houses and even state governments. They are the wealthiest dragonmarked house by far and their banking establishments can be found all over Khorvaire.
- House Lyrandar: House Lyrandar is a dragonmarked house of half-elves in Khorvaire with its enclave located on Stormhome, an island city-state just north of Aundair. House Lyrandar possesses the Mark of Storm. This mark grants various magical benefits that allow its bearers to control winds and waves.
- House Medani: House Medani is a dragonmarked house of half-elves and is known as the smallest and one of the youngest houses. However, despite its size and age, its members are seemingly everywhere, working as operatives in various fields such as guards, researchers, advisers, inquisitives and spy-catchers. Unlike most dragonmarked houses, Medani has a strong geographical location as the majority of its members are Brelish nationals and live in Breland.
- House Orien: House Orien is a dragonmarked house of humans in Khorvaire, with its major enclave located in Passage, Aundair. The house specialises in courier services and land based transport. Though House Cannith invented the lightning rail, House Orien are the ones who operate and manage it.
- House Phiarlan: House Phiarlan is an dragonmarked house of elves in Khorvaire, although they are now based in Sharn, their former base of operation in Cyre having been destroyed in the Day of Mourning. To the public, Phiarlan is a house of entertainment comprised of bards, actors, artists and acrobats, though it is secretly a house of spies.
- House Thuranni: House Thuranni is the youngest of the dragonmarked houses. They were once a part of House Phiarlan and have become their direct rivals competing in entertainment and espionage. House Phiarlan is still larger and stronger than House Thuranni, leading the way in information gathering and spying however, House Thuranni surpasses Phiarlan in assassinations.
- House Sivis: House Sivis is the dragonmarked house of gnomes strongly based out of Zilargo. while most people are suspicious of the devious and conniving nature of gnomes, House Sivis has remained firmlu neutral in all conflicts and their services are now considered indispensible. The House is currently governed by a High Council composed of representatives from each of the nations in which the House operates; this council is currently led by Lysse Lyrriman d'Sivis. Lady d'Sivis has led the House for nearly 90 years, since nearly the beginning of the Last War.
- House Tharashk: House Tharashk is a dragonmarked house of half-orcs and humans that has just recently begun spreading throughout Khorvaire, though it is still heavily based in The Shadow Marches. The house is the second youngest of the dragonmarked houses. Its members are renowned prospectors, bounty hunters, and inquisitives. Tharashk is the only house to hire monstrous laborers and mercenaries from Droaam, with whom they have an alliance. Lhara d'Aela is a dragonmarked heir of House Tharashk, a member of the Finder's Guild and Clifftop Adventurer's Guild, and the owner of the Careless Whisper Tavern and Inn.
- House Vadalis: House Vadalis is a dragonmarked house of humans in Khorvaire. Their main operation is centered in the Eldeen Reaches, having migrated there almost 2,000 years ago. The house's most significant trade is in the breeding and training of animals.