House Diedne was a founding house of the Order of Hermes, originally the most powerful of the founding Houses.
It was a pagan, druidic, non-Latinate House that contributed Spontaneous Magic to the knowledge taught at founding of the Order.
In very early eleventh century hostilities broke out between it and magi of primarily houses Flambeau and Tremere, in large part due to suspicions of practice of human sacrifice that manifested often as the calling for Wizard Wars against Diedne Magi. The hostilities escalated into the Schism War, which concluded with the death or disappearance of all magi of House Diedne.
Although the House itself is considered extinct (as no one has been confirmed to have been Marched for being a Diedne for several decades), its legacy has not been forgotten and may be found in many ways even in the current day.
There have been murmurs since the last Grand Tribunal (in 1195) to Rehabilitate Diedne and lift the March that was ordered against it.
House Relationships
In most situations, House Diedne kept cold relations with House Flambeau and particularly House Tremere, while keeping warmer ties with House Merinita and House Bjornaer. Its relationship to House Verditius was mostly neutral.
Many on the ranks of House Ex Miscellanea mistrusted House Diedne due to conflicts in Britain that predated the founding of the Order. Perhaps ironically, both Houses ended up developing an affinity for receiving Hedge Wizards into their ranks.
House Bonisagus was sharply divided in its feelings for House Diedne. while House Guernicus had historically been very friendly to House Diedne despite ending up taking the decision to renounce it and even betraying its representative at the Grand Tribunal of 1011.
Current opinions along the Order of Hermes as a whole are at least somewhat sympathetic to House Diedne, at least outside of House Tremere. There has not been enough expressed sympathy,however, for anyone to risk bringing up a repeal of the March of Diedne.