Kilij Arslan II ruled the Sultanate of Rum for thirty-six years, destroyed Manuel I Komnenos's invasion at Myriokephalon in 1176, and then divided his sultanate among eleven sons.
Kilij Arslan II inherited a sultanate in 1156 that was one Turkish power among several in Anatolia, hemmed in by the Danishmendids to the east and by a Byzantine Empire under Manuel I Komnenos that was more capable and more aggressive than it had been for a century.
He spent twenty years managing that position — submitting to Manuel when he had to, including a famous and much-described visit to Constantinople in 1162, and expanding at Danishmendid expense when he could.
In 1176 Manuel came for him with the largest army the empire had put into Anatolia since Manzikert. Kilij Arslan let it into the pass at Myriokephalon and destroyed it, and the Anatolian question was settled for good.
The Byzantine sources, which are the fullest we have and are hostile, present him as clever, patient and thoroughly untrustworthy — a man who made agreements he intended to break and flattered an emperor he was measuring.
That is a portrait drawn by the losing side, and what it actually describes is a ruler in a weak position who used diplomacy to buy the twenty years he needed. His 1162 visit to Constantinople, where Manuel entertained him lavishly and extracted promises, reads in the Greek accounts as a submission; in the event, none of the promises constrained him.
The decision that defines him is not the battle but what he did after it. Dividing the sultanate among eleven sons in the 1180s, each with a province, was a Turkish practice with its own logic — but he was old, they were rivals, and the result was that the state which had just beaten the Roman Empire spent the next generation at war with itself.
Manuel invaded in 1176 aiming at Konya itself, with a large army encumbered by a siege train. Kilij Arslan offered terms on the march and Manuel refused them, which every account treats as the decisive error.
The Byzantine column entered the pass at Myriokephalon strung out over a long distance, and the Turks held the heights on both sides. What followed was less a battle than the destruction of a column that could not deploy: the siege train was lost, the rear was cut up, and Manuel — by his own admission afterwards — considered abandoning the army.
Kilij Arslan then offered terms again, and this time took them: the emperor was allowed to withdraw in exchange for demolishing two frontier fortresses. Letting a beaten emperor go was a choice, and a shrewd one — a dead Manuel would have been replaced by an unknown, and a live humiliated one was worth more.
From about 1186 he divided the sultanate among his sons, keeping Konya. It did not work for a day longer than he was strong enough to enforce it.
The sons fought each other, and in 1190 the sultanate had to face Frederick Barbarossa's crusade — the largest army to cross Anatolia since the First Crusade — while divided. Barbarossa took Konya in May 1190 and passed on through, which he could not have done against a united Rum.
By 1192 Kilij Arslan was in the custody of one son and being moved about by another. He died at Konya that year, and the sultanate took twenty years to reassemble itself under his son Kaykhusraw I.
Myriokephalon is his monument and it is a curious one. Militarily it was less catastrophic than Manzikert — the army escaped, the emperor lived, no territory changed hands directly — and strategically it mattered more, because after it no Byzantine emperor ever again seriously attempted to reconquer Anatolia.
Manuel himself understood this. His letter to Henry II of England comparing the defeat to Manzikert is the empire's own verdict, and the reason the archive treats the two battles as a pair.
His türbe stands in the courtyard of the Alâeddin Mosque on the citadel at Konya, among the tombs of the sultans of Rum — the building his dynasty is remembered by, in the city his father made its capital.