Sovereigns of the Leashed Flame

The  were a group of twenty or more Long in England in the fifteenth century who made a treaty with the Forge of Days. Under their rule, England became devoted to the worship of the Forge (under the name St. Spark or the Leashed Flame), and attempted to conquer the world. After their defeat, the Leashed Flame inspired the Society of the Noble Endeavour, who sought to become Long through ascension.

Fort Geryk may have been an outpost of the Sovereigns of the Leashed Flame, as it references an empire which does not exist "in any reputable History" and gives items closely related to the Forge of Days.

War of the Roads
The War (or Wars) of the Roads is a term for the conquest waged by the Children of the Leashed Flame against the rest of the world in the fifteenth and sixteenth centuries. Though initially successful, the Sovereigns' fortunes faltered when the Church of the Unconquered Sun joined forces with the Sisterhood of the Knot to defend against the conquests. The Sovereigns burned the martyr-legions of the Sisterhood (presumably using powerful magics), and might have gone on to conquer the rest of the world had they not lost control of the Forge of Days. Unleashed, the Forge devoured the Sovereigns, putting an end to their ambitions and to the War of the Roads.

The War of the Roads was fought in the Mansus as well as the waking world. The Church and the Sisterhood allied with the Vagabond, and the Forge of Days also fought the Red Grail, one of the Hours venerated by the Sisterhood. Implicitly, the Forge may have also fought the Ring-Yew, Horned Axe, and perhaps Thunderskin (the other Sisterhood Hours). If so, it is likely that it additionally fought the Sun-in-Splendour, to whom the Church of the Unconquered Sun was dedicated.

The War of the Roads was originally foretold in India, prior to India's conquest by the Great Hooded Princes.