Lore:Horn of Summoning
The Horn of Summoning was an artifact of little information, but said to wield immeasurable power. Legends regarding the horn date back to the early First Era. It has been attributed to the liberation of High Rock during their occupation of the First Empire of the Nords. King Edward of Daggerfall and King Moraelyn utilized the horn to free the Bretons and expel the Nords. Its whereabouts are unknown, while it was widely believed it was hidden underneath Daggerfall in a series of caves, or that it was in the safekeeping of Ephen, a god of Mournhold and half-brother of Moraelyn. But in actuality, Tiber Septim claimed the horn from Morrowind and left the Staff of Chaos in Ephen's tomb underneath Mournhold.
According to legend, the Horn of Summoning was used by Edward and Moraelyn to repel the Nords from High Rock in the early First Era. From then on it was kept by King Edward in Daggerfall, but eventually, he passed away and gave it to his friend, Moraelyn, who later gave it to Ephen for safekeeping. Many years later, Tiber Septim invaded the province of Morrowind in the late Second Era, part of his many conquests known as the Tiber Wars. The Emperor claimed the Horn of Summoning from Morrowind, and left the Staff of Chaos in Mournhold's possession, which unintentionally fueled the rivalry between Mournhold and Ebonheart.
Since then the Horn's location has been lost to time, deduced to either Daggerfall's vast underground, or Mournhold's inner caves. In the mid-late Third Era, Queen Barenziah was swayed by a figure known as the Nightingale to delve into Ephen's tomb to claim the "Horn of Summoning," a topic that the Queen had studied extensively. In reality, the Queen led the Nightingale to the Staff of Chaos, instead of the Horn. The rogue vanished, when the Staff came into the possession of Jagar Tharn. Symmachus was extremely relieved that the Nightingale had the Staff rather than the Horn.