Dragonmarked houses are organizations that are based on bloodlines descended from families that first manifested dragonmarks. Not all members of the Houses have dragonmarks; nor is it an assurance of power. Talent is considered a better choice. Most common people have at least a small amount of House blood in their ancestry, usually unnoticed.
The Dragonmarked Houses are the cornerstone of the economy of Khorvaire. Most banking, security, communications, transportation and fabrication are run by the Dragonmarked Houses. The Houses use their exclusive access to the powers of dragonmarks to sustain their economic empires that extend far beyond arcane powers of the dragonmarks themselves. The houses can attribute most of their success to their meticulously crafted reputations for standardization and quality that have elevated bearers of dragonmarks with a status that mundane wizards and artificers cannot possibly match.
The source material states that each of the houses are not traced back to a single member bearing a certain mark, rather that certain marks manifested in certain regions on specific races and families. After several generations these families began to understand the significance of each individual mark and came to see certain marks as “true marks”, marks that breed true in a bloodline. Aberrant marks are those that manifest as a consequence of interbreeding of bloodlines.
Ultimately the true bloodlines would wage war on those with aberrant marks in a conflict known as the War of the Mark. The results of this conflict would unite the true bloodlines officially into the current houses represented and lead to a founding of the council known as the Twelve. The Twelve would become responsible for codifying the traditions of the dragonmarked families and set forth the standards by which the current houses are governed.
Eventually a man who famously became known as Galifar I would succeed in uniting the continent together into the nation of Galifar, the house leaders would come together in the city of Korth and make arrangements with the would-be-king that would limit their political power in exchange for assurances of their continued economic strength. These would become known as the Korth Edicts and would last for a thousand years and were designed to prevent members of any of the dragonmarked houses from creating standing armies (excepting House Deneith to provide mercenary services), disallowing members of the houses from marrying into the aristocracy of Galifar, and insuring that no house could hold a grant of land.
By the time the Last War was in full swing, the Korth Edicts would be set aside allowing house enclaves to maintain forces and by the end of the war several houses now have large land holdings of their own. Many of the houses themselves were said to wield as much power as the nations themselves and it is doubtful any of the twelve new nations have enough power to enforce the terms or renegotiate the edict.
Mark of Making: 3500 years old.
Tinkers Guild: repairs and maintenance
Fabricators Guild: construction and production
Heraldic beast: Gorgon
Month/Moon: Eyre (Mid-spring, ~April, fourth moon)
Dragonmark Abilities: The Mark of Making grants the power to mend or fabricate material goods.
The mark of making first appeared in the Eberron setting approximately 2500 Years before the foundation of the Kingdom of Galifar and has always distinguished itself as the leader amongst the other dragonmarked houses. They are considered to be the foremost experts in dragonshards and best known for the invention of everbright lanterns, lightning rail and the race of warforged. Their success is due to their ability to mass-produce magical wares at reasonable prices.
As of the current time period in the setting, the house is divided into three distinct factions that are vying for control of the house in the wake of the destruction of the nation of Cyre. Cannith South is ruled by Merrix d’Cannith from the city of Sharn, Cannith West is ruled by Jorlanna d’Cannith from Aundair, and Cannith East which is ruled by Zorlan from Karnnath.
Mark of Sentinel: 3600 years old.
Defenders Guild: Protection
Blademarks Guild: Hirelings and mercenaries
Heraldic beast: Chimera
Month/Moon: Olarune (Late winter, ~February, second moon)
Dragonmark Abilities: The Mark of Sentinel grants various powers related to personal protection.
House Deneith operates under a strict military hierarchy. Since all houses have vowed to stay neutral in conflicts, House Deneith supplies to both sides of a conflict. It is also the only house allowed to maintain an active army. Because of its mercenary forces, Deneith holds the most significant military power among the dragonmarked houses. In the past, it has strictly abided by its vow of neutrality, selling its services to those on both sides of any conflict. With the Five Nations weakened by the Last War, some within the house feel that it is time for Deneith to exercise its power to forge a new kingdom.
Mark of Hospitality: 3200 years old.
Hostelers Guild: bars and inns.
Heraldic beast: Blink dog.
Month/Moon: Nymm (Early summer, ~June, sixth moon).
Dragonmark Abilities: ability to manipulate arcane energy to generate shelter and sustenance.
Although most halflings are nomadic, the members of House Ghallanda operate an impressive number of entertainment institutions, all over Khorvaire. Members of the Hostelers guild include innkeepers, chefs, and restaurateurs, as well as inspectors who enforce standards and regulate business for all member establishments—those run by the house as well as those independent inns and restaurants willing to earn the house seal and display it for all to see.
Mark of Healing: 3000 years old.
Healers Guild: health.
Heraldic beast: Griffon.
Month/Moon: Therendor (Early spring, ~March, third moon).
Dragonmark Abilities: healing; depending on the size of the dragonmark, the individual can be restricted to healing small wounds, or to curing major diseases, even regenerating lost limbs
House Jorasco provides mundane health care services to the public, as well as magical healing to those who can afford it. Common people visit House Jorasco hospitals instead of churches, since clerics generally reserve their healing abilities for the faithful.
Mark of Warding: 2500 years old.
Banking Guild: money, loans and safekeeping.
Warding Guild: security and protection.
Heraldic beast: Manticore.
Month/Moon: Vult (Early winter, ~December, twelfth moon).
Dragonmark Abilities: ability to lay magical alarms and traps.
House Kundarak operates out of the Mror Holds, running the banking and moneylending business in Khorvaire. With close ties to House Sivis, all kinds of coin exchange, credit and safekeeping services are provided by House Kundarak.
Mark of Storm: 2000 years old.
Raincallers Guild: provides good weather for farmers.
Windwrights Guild: transport over water or through the air.
Heraldic beast: Kraken.
Month/Moon: Zarantyr (Mid-winter, ~January, first moon).
Dragonmark Abilities: power over wind and weather.
House Lyrandar members have the power to manipulate the weather, and have used that power to create an island paradise for themselves, off the coast of Aundair (called Stormhome).
Mark of Detection: 1500 years old.
Warning Guild: protection with prescience.
Heraldic beast: Basilisk.
Month/Moon: Lharvion (Mid-summer, ~July, seventh moon).
Dragonmark Abilities: bearers of this mark can sense hidden threats, such as poison.
Because the members of House Medani can see trouble coming, they are very effective in personal security. Its magic item inventions were instrumental in ending the War of the Mark.
Mark of Passage: 3000 years old.
Couriers Guild: postal service.
Transportation Guild: freight.
Heraldic beast: Unicorn.
Month/Moon: Aryth (Late autumn, ~November, eleventh moon).
Dragonmark Abilities: dependent upon the size of the mark, bearers may possess great speed, the ability to fly or even teleportation.
Members of House Orien control the Lightning Rail and several caravan routes. House Orien are masters of trade maintaining trade along a vast network.
Mark of Shadow: 3000 years old.
Entertainers and Artisans Guild: entertainment.
Heraldic beast: Hydra.
Month/Moon: Sypheros (Mid-autumn, ~October, tenth moon).
Dragonmark Abilities: powers over illusion, deception and scrying.
Part of House Phiarlan split off recently, to form House Thuranni. The Mark of Shadow grants divinatory and illusory powers to those who possess it. The Entertainers and Artisans Guild of House Phiarlan provides gifted members of both professions with gainful employment. The house’s true work, done in secret, involves information brokering and espionage.
Mark of Scribing: 2800 years old.
Speakers Guild: diplomatic services and translation.
Notaries Guild: notary services.
Heraldic beast: Cockatrice.
Month/Moon: Rhaan (Early autumn, ~September, ninth moon).
Dragonmark Abilities: power over written and spoken word. Through use of dragonshards, can communicate over vast distances with the speed of the wind.
The members of House Sivis guarantee the authenticity of documents. It is known for its impartiality, and is relied on to send sensitive information securely. It is also known for its bureaucratic red tape.
Mark of Finding: 1000 years old.
Finders Guild: finding.
Race: Human and Half-Orc.
Heraldic beast: Dragonne.
Month/Moon: Barrakas (Late summer, ~August, eighth moon).
Dragonmark Abilities: can track things that are lost or hidden through use of their mark.
The members of House Tharashk are highly skilled trackers and bounty hunters. They are also in the mining business, and control most of the trade with Eberron dragonshards.
Mark of Shadow: 25 years old.
Heraldic beast: Displacer beast.
Month/Moon: Sypheros (Mid-autumn, ~October, tenth moon).
Dragonmark Abilities: power over illusion, deception and scrying.
Like its parent, House Phiarlan, House Thuranni is in entertainment business. The members left Aerenal and travelled to Khorvaire around the time of the destruction of House Vol.
Mark of Handling: 1800 years old.
Handlers Guild: breeding.
Heraldic beast: Hippogriff.
Month/Moon: Dravago (Late spring, ~May, fifth moon).
Dragonmark Abilities: animals bred by those bearing the Mark of Handling are more intelligent, stronger, faster and more powerful than those bred and/or trained by those without the aforementioned mark.
The members of House Vadalis breed any number of animals, mostly mounts, but also animals used in offense or defense, or pets. House Vadalis operates out of the Eldeen Reaches.