Esperacchius

Esperacchius, also known as Sword of Hope, and in legend as Durendal is one of the Swords of the Cross. It's first seen in Death Masks.

Description
"Like ‘love,’ ‘hope’ is one of those ridiculously disproportional words that by all rights should be a lot longer."

- Dresden thinking to himself

Though it has been reworked since its creation, Esperacchius currently looks like a cavalry saber, and bears the hieroglyph for the Sun on the pommel. Its weakness is to be wielded in despair, and will be destroyed by such an action.

The spirit of Sir Stuart Winchester confirmed that Esperacchius is the legendary Frankish sword Durendal, Its current wielder is Sanya.

History
Durendal's first wielder was Roland the Frank, the chief paladin of Charlemagne and a symbol of hope for France against the Spanish Saracens.

At a later time, it was wielded by a man known as "the Egyptian", briefly mentioned in Death Masks, and killed by Ursiel.

Afterwards, it was wielded by Sanya, who was given the sword by the Archangel Michael after giving up his Denarian coin.

Mythology
Indestructible and capable of cutting through rock, Durendal is the sword of Roland, legendary paladin of Charlemagne in French epic literature, and it is reputed to have belonged to young Charlemagne at one point, and, passing through Saracen hands, came to be owned by Roland.

The sword has been given various provenances. Several of the works of the Matter of France agree that it was forged by Wayland the Smith, who is commonly cited as a maker of weapons in chivalric romances. It has, however, been reported as being brought to Charlemagne by an angel.

In the series
As of Skin Game, Esperacchius remained in the care of Sanya. Between the time of Michael Carpenter being injured on Demonreach and Waldo Butters picking up Fidelacchius, it was the only sword being wielded by a Knight of the Cross; Sanya has stated that he did not know how long he could stem the tide of darkness alone.

Death Masks
In Death Masks,

Proven Guilty
In Proven Guilty,

Small Favor
In Small Favor,

Ghost Story
In Ghost Story,

Skin Game
In Skin Game, it is wielded against Denarians Magog and Shaggy Feathers in Iran, to prevent it to be used against Nicodemus Archleone's party in the break-in in Hades' Vault.

Word of Jim
"Sanya’s sword actually has an Egyptian hieroglyph for the Sun on the pommel, and he could use it as a letter-seal if he was of a mind to do it. The Egyptian, who had the sword before Sanya, often did. Sanya isn’t really the wax-seal-letter-writing kind."

- Jim Butcher

External references

 * Durendal: The Holy Sword of Roland
 * Badass of the Week: Count Roland
 * Biography of Roland
 * - Wikisource
 * Song of Roland Background - GradeSaver