Not to be confused with Teclis.
- "The Phoenix King Tethlis was a mighty warrior, maybe the greatest warrior-king there ever was. His deeds are legend amongst the High Elves of Ulthuan."
- —Tethlis the Slayer.
Tethlis the Slayer, known as the Hero of Griffon Gate, was the sixth Phoenix King of Ulthuan, as well as the third to originate from the Kingdom of Caledor. Tethlis had learned well the value of preparation and organisation from his predecessor, Caradryel, and he came to the throne with one aim: to force the Dark Elves out of Ulthuan, and reclaim the Blighted Isle from the spawn of Naggaroth. He followed his plan through with single-minded ruthlessness and determination.[1a]
Tethlis' heart was filled with a terrible, cold hatred for the children of Naggaroth, for they had slain his family in one of their many raids. Thus did the Dark Elves forge their most implacable of enemies. Tethlis fought not for honour or glory. He sought only to end the threat of Naggaroth for all time, and he might have succeeded had it not been for the decline in power of the Dragons. During the later part of Caradryel's reign, the Dragons had become increasingly rare. For reasons unknown, many had started to drift into longer and longer sleeps, waking perhaps once per century. The Elves needed to increase their strength in other areas to compensate for losing the raw power and savage strength of the great beasts.[1a]
The first years of Tethlis' reign saw the assembling of new armies. Every Elf city was required to have a martial field where its soldiers could train and fight mock battles. Painstakingly, with meticulous attention to detail, Tethlis rebuilt the Elf forces to a strength not seen since the time of Aenarion. He never committed an army to the field without being sure that he could bring overwhelming force to bear and never fought a battle without being sure he could win it.[1a]
When this was complete, Tethlis launched The Scouring, a long campaign to drive the Dark Elves out of Ulthuan. The armies of Ulthuan and Naggaroth waged war against each other for centuries, the course of the war changing on the outcome of a single battle. The war reached heights of ferocity not seen since the days of the Sundering, as seen at the siege of Griffon Gate, where a Druchii army was ambushed by Tethlis' forces: only a counter-attack led by Malekith himself was enough to save the Dark Elves from destruction, or the siege of Tor Lehan, where the Asur and Druchii forces wiped each other out down to the last Elf, leaving no survivors.
By relentless attrition he wore the Dark Elves down. Over the long centuries, a series of massive offensives rolled rolled them back through the Shadowlands and eventually culminated in the storming of Anlec. Tethlis was cold and ruthless, even by the standards of Elves. He ordered the entire city razed. No prisoners were taken. Salt was strewn in the fields. Shocked though his subjects were, they obeyed. No Dark Elf was left alive on Ulthuan.[1a]
Having scoured Ulthuan, Tethlis turned his attention to the Blighted Isle, which was still in the hands of the Witch King's legions. The largest Elf armada of all time was assembled to reclaim it. Hundreds of ships bore many thousands of troops out to sea. Elf mages bound the weather and kept the skies clear of storms. The seas were swept clear of Naggarothi ships. On the shores of the Blighted Isle, the Dark Elves host assembled, determined to deny the High Elves a foothold on the shore.[1a]
The Elves landed and thus began the Battle of the Waves, in which the swirling tides turned red with blood. Both sides fought with abandon, crimson water swirling round their knees. The skies were black with arrows and crossbow bolts, and the wounded were trampled and drowned in the shallow waves. Inch by bloody inch, the High Elves fought their way onto the beach and overran the island, driving their fark kinsfolk into the sea. The carnage was ghastly. Dark Elves were butchered by the thousand until even the hardiest Elf captains were sickened. They feared that their troops might acquire a taste for such butchery and become no better than those they fought against. With a great victory won, Tethlis at first insisted that the army push on to Naggaroth, but as the army moved northward he found himself drawn, by some irresistible influence, to the Altar of Khaine.[1a]
On his journey through the Plain of Bones, Tethlis saw something glitter. Strangely drawn to the light, he unearthed the Dragon Armour of Aenarion. Of Aenarion or Indraugnir there was no other trace to be found. The armour, he gifted to Auaralion, the great grandson of Morelion, Aenarion's son by Astarielle. This was virtually his last act as Phoenix King.[1a]
There are two versions of what happened when Tethlis at last came before the Widowmaker. Some records say that he dismissed the White Lions and the rest of his retinue, claiming that he wanted a moment alone to contemplate the blade that had done his people so much harm. It is said that a Dark Elf Assassin emerged from his hiding place beneath the piles of bones and struck Tethlis down with a poisoned blade. Others say that Tethlis, determined to end the was with the Dark Elves, grasped the Sword of Khaine and that it writhed in his grasp and started to come free, and that the king was cut down by his own bodyguard, who feared the consequences of Aenarion's fatal weapon being unleashed once more upon the world.[1a]
No-one knows for sure exactly what happened. Scholars are divided. All that is known is that Tethlis dies that day, and lacking his driving presence, the armada turned back from Naggaroth.[1a]