The Thorn Brotherhood is a known super villain group, and operates worldwide.
Information gained over the years points to the Brotherhood originating with Xavier Thorne, a known arcanist and former chair member of the Coalition of Magic. He disappeared in late 1850, and was not seen again until the late 1990s.
The first recorded appearance of the Brotherhood was in March 1873, recorded by a Coalition mage who survived an assault by people covered to varying degrees in spines. He reported that the one directing this assault had glowing eyes, and a strong power emanating from between his shoulder blades. The attack claimed thirteen lives, and four magical artefacts went missing. Their names were never disclosed to any authority, and are still held secret by the Coalition.
The Brotherhood rose to public enmity in 1902, when their leader, calling himself Father Thorn , announced an attack on Boston. The metahumans of the time, few as they were, rallied to aid the armed forces in repelling the attack. The Coalition broke their usual rule of non-interference and joined the assembled forces. The assault was repelled, but afterwards it was discovered that even though the forces fought off were numerous and powerful, they served as a distraction for the theft of Plymouth Rock.
With the Coalition having revealed itself to the modern world, a campaign was launched against the Brotherhood, focusing on the recovery of the stolen artefacts. In 1912, the campaign came to a head, with Father Thorn and all of his generals being killed in a massive raid on the Brotherhood headquarters located in a hidden tunnel system underneath the Northeast United States. Plymouth Rock and all stolen artefacts were recovered, and the Brotherhood was thought disbanded.
The Brotherhood faded from knowledge until 1997, when a series of simultaneous attacks were conducted against Universities in the U.S.A. known to house Coalition towers. The attacks were all eventually repelled, but not before towers in California and New York were destroyed. The Coalition attempted to rally a counter-attack, calling out to the superhero community to aid them. The aid was minor at first, the feeling being that the Brotherhood was a magic problem. The Coalition did their best to locate the Brotherhood, but the organisation disappeared again for another year.
In May of 1998, two giant spires comprised of an unknown substance erupted from the sites of the destroyed towers in California and New York. Almost immediately, the superhero community responded, attempting to investigate the spires. The spires then shattered, scattering fragments across a two hundred mile radius each. Each fragment that contacted a living person immediately converted them into a member of the Brotherhood, and metahumans underwent transformations into commanders. Father Thorn appeared at the site of the New York spire and declared that the Thorn Brotherhood had risen again to claim North America as their home, and revealed himself to be Xavier Thorne. Immediately afterwards, he issued a challenge to the Coalition, declaring war upon them and promising that they would be exterminated and replaced by the Brotherhood as the magical authority for Earth. The Thorn War had begun in earnest.
The War lasted four months, and by the end the Brotherhood had control of half of the continental landmass of North America, with Spires serving as bases of operation. Father Thorn made a reappearance to lead his Brotherhood. The War’s turning point is said to be the capture of Paragon, who had been converted at the New York Spire. Using him, the Coalition and Infinite Enterprises were able to engineer a techno-magic device able to produce a pulse that would disintegrate fragments across the entire North American continent. It also served to destroy the Spires safely, and the Brotherhood was thought destroyed once again.
This proved false, as the Brotherhood once more made a reappearance in 2038. Their activity has not been as grand as previous appearances, and are mostly concerned with small strikes against seemingly random targets. No one has been able to confirm if Father Thorn has reappeared with the Brotherhood, but the Coalition is insistent that he must be leading them.