The history of the Seljuk Sultanate of Rum is filled with powerful rulers, devastating wars, family rivalries, political assassinations, and mysterious deaths. Although these sultans ruled the same empire, very few were able to live out their lives peacefully. Some died on battlefields. Others were poisoned, drowned, strangled, executed, or simply disappeared from the historical record. As the centuries passed, the greatest threat to the Seljuk throne increasingly came not from foreign enemies, but from within the ruling family itself. From Suleiman I to Mesud III, the story of the Seljuk Sultans of Rum is almost a two-hundred-year map of war, succession struggles, and political violence.
Suleiman I: The Founder Who Died Fighting a Relative
The story begins with Suleiman I, the founder of the Seljuk Sultanate of Rum. He established his power in Anatolia and made Nicaea his capital.
But his biggest challenge came from another member of the Seljuk family: Tutush I, who ruled in Syria.
In 1086, the two relatives came into conflict near Aleppo. At the Battle of Ain Salm, Suleiman was defeated and killed.
The founder of the new state therefore never got the chance to grow old in the empire he had created. His reign ended on a battlefield while fighting another member of his own dynasty.
After his death, the throne remained uncertain for a period, with power being managed by regents until another member of the family could take control.
Kilij Arslan I: Drowned While Escaping Battle
The next major ruler was Kilij Arslan I, the son of Suleiman I.
Much of his reign was spent fighting the Crusaders, and he successfully resisted several of their campaigns. However, his final battle came against a different enemy.
In 1107, Kilij Arslan marched toward Mosul and encountered Muhammad I Tapar, the Great Seljuk Sultan.
Kilij Arslan was defeated near the Khabur River. While attempting to escape on horseback, he fell into the river and drowned.
His death was therefore not caused by an enemy sword. He died in the water while trying to escape the battlefield.
Malik Shah: A Sultan Lost to Dynastic Struggle
Kilij Arslan I’s son, Malik Shah, inherited a deeply unstable political situation.
Before becoming sultan, Malik Shah had spent years as a prisoner in Isfahan. Once he finally gained the throne, however, his greatest enemies were once again members of his own family.
He lost territory to the Byzantines and struggled to maintain control. Eventually, his brother Mesud I defeated him and took the throne.
The exact fate of Malik Shah remains unclear. Historical records do not provide a definite account of how or when he died after losing power.
Mesud I: One of the More Stable Reigns
Mesud I proved to be one of the more successful and stable rulers of the early Sultanate of Rum.
He defeated internal rebellions, resisted the Second Crusade, and continued expanding and defending Seljuk authority for decades.
Unlike many rulers who followed him, Mesud did not die in a dramatic assassination or battlefield incident.
He died in 1156, apparently of natural causes, although the exact cause of death was not recorded.
Kilij Arslan II: The Decision That Created Civil War
Kilij Arslan II became one of the most powerful sultans of Rum.
He defeated the Byzantines at the Battle of Myriokephalon and greatly strengthened Seljuk control over Anatolia.
But his approach to succession created a problem that would haunt the dynasty for decades.
Instead of leaving his territory to a single successor, Kilij Arslan divided his lands among his eleven sons.
The result was not peace.
His sons began fighting among themselves, creating a major succession struggle. Kilij Arslan died in 1192, during the siege of Aksaray, as the political chaos he had helped create was already consuming the dynasty.
Kaykhusraw I: A Throne Lost, Then Regained
After Kilij Arslan II’s death, his son Kaykhusraw I initially became sultan.
But he could not hold the throne.
His brother Suleiman II defeated him and forced him into exile.
Kaykhusraw’s first reign therefore ended not with his death, but with his removal from power.
However, his story was far from over.
Suleiman II: A Reign Ending After Defeat
Suleiman II ruled next.
In 1204, he suffered a major defeat against the Georgians at the Battle of Basiani. He died later that same year.
Historical sources connect his death with this period of military defeat, although they do not provide enough certainty to say that he was killed directly in the battle.
Kilij Arslan III: The Sultan Who Disappeared
Suleiman II’s son, Kilij Arslan III, inherited the throne.
His reign lasted barely a year.
His exiled uncle, Kaykhusraw I, returned to Anatolia, challenged him, and successfully reclaimed the throne.
After that, Kilij Arslan III effectively disappears from the historical record.
His ultimate fate remains unknown.
Kaykhusraw I: Killed in Single Combat
Kaykhusraw I’s second reign proved far more significant.
In 1211, he confronted the Byzantine ruler Theodore I Laskaris at the Battle of Antioch on the Meander.
According to the traditional account, the two rulers engaged in single combat.
Kaykhusraw was defeated and killed by Laskaris himself.
His death is therefore one of the clearest examples on the list of a Seljuk sultan dying directly in combat against another ruler.
Kaykaus I: A Natural Death
Kaykhusraw I was succeeded by his son Kaykaus I.
Once again, however, the succession was complicated by family rivalry. Kaykaus had to deal with his brothers, including the future sultan Kayqubad I.
Eventually, he secured his position and ruled until 1220.
Unlike several of his predecessors, Kaykaus died of natural causes. The exact illness or medical cause was not recorded.
Kayqubad I: The Sultan of Rum’s Golden Age
For many historians and enthusiasts of Seljuk history, Kayqubad I represents the height of the Sultanate of Rum.
During his reign, Seljuk territory expanded, trade flourished, and important cities and fortifications were developed throughout Anatolia.
Yet even during this period of strength, the succession problem remained unresolved.
In 1237, Kayqubad died suddenly at his palace, the Kayqubadiyya Palace, after being poisoned.
Traditional accounts have often connected his death with his son, Kaykhusraw II, who wanted to secure the throne.
After Kayqubad’s death, Kaykhusraw moved quickly to eliminate potential rivals, including his brothers.
The death of one of Rum’s strongest rulers therefore became another example of how dangerous dynastic succession had become.
Kaykhusraw II: The Beginning of the End
Kaykhusraw II inherited the throne after his father’s death.
His reign marked a dramatic turning point for the Sultanate of Rum.
The Baba Ishak uprising seriously weakened the state from within. Then came the devastating Battle of Köse Dağ in 1243.
The Seljuks suffered a crushing defeat against the Mongols, and the Sultanate effectively became a Mongol vassal.
Kaykhusraw died in 1246, only a few years after the disaster at Köse Dağ.
His death was not recorded as a violent assassination. Instead, it came after years of political and military crisis.
Kaykaus II: A Sultan Forced Into Exile
After Kaykhusraw II’s death, his three sons became involved in a complicated struggle for power.
Kaykaus II initially ruled jointly with his brothers, while Mongol influence over the Seljuk state continued to increase.
Eventually, Kaykaus lost the struggle and fled into Byzantine territory.
He later settled in territory associated with the Golden Horde in Crimea, where he lived in exile.
He died around 1279, apparently of natural causes.
His story shows just how dramatically the authority of the Seljuk throne had declined. A ruler who once commanded Anatolia ultimately spent his final years far from the center of power.
Kayqubad II: A Mysterious Death
Kaykaus II’s brother, Kayqubad II, also shared power during this turbulent period.
By this time, Mongol influence over the Sultanate had become increasingly powerful.
Around 1256, Kayqubad II was found dead while traveling.
The exact cause of death remains uncertain.
Some historical interpretations have suggested assassination, but there is no definitive evidence establishing exactly what happened.
His death remains another mystery in the history of the Seljuk dynasty.
Kilij Arslan IV: Strangled in a Political Execution
Their brother Kilij Arslan IV eventually became the senior ruler, backed by the Mongols.
But his relationship with powerful Mongol officials became increasingly dangerous.
One of the most influential figures was Pervane, a powerful Mongol-appointed statesman.
In 1266, Pervane had Kilij Arslan IV strangled.
This was no battlefield death.
It was a political execution carried out because Pervane feared that the sultan might move against him.
The event demonstrates how much real power had shifted away from the Seljuk throne.
Kaykhusraw III: A Child Sultan Executed by the Mongols
Kilij Arslan IV’s son, Kaykhusraw III, became sultan while still a child.
By this stage, however, the title of sultan had lost much of its former authority. Real political power increasingly rested with Mongol authorities and their representatives.
In 1284, Kaykhusraw III was accused of involvement in a rebellion.
The Mongols ordered his execution.
A child who formally occupied the Seljuk throne was therefore killed by the very imperial power that dominated the state.
Mesud II: A Sultan Without Real Power
After Kaykhusraw III’s execution, the Mongols installed Mesud II as sultan.
He was unable to restore the strength of the old Seljuk state.
By 1297, he had been removed from power.
Yet his connection with the throne was not finished.
He would eventually return for a second reign.
Kayqubad III: Another Political Killing
After Mesud II was removed, his nephew Kayqubad III became sultan.
He attempted to strengthen his position by removing officials who supported his predecessor.
This quickly created enemies.
In 1302, while visiting the Mongol Ilkhan, the decision was made to execute Kayqubad III.
Once again, the death of a Seljuk ruler had little to do with a foreign battlefield.
The sultan was eliminated through the political machinery of the Mongol-controlled state.
Mesud II Returns to the Throne
After Kayqubad III’s death, Mesud II returned for a second reign.
But by this point, the Seljuk Sultanate of Rum was little more than a shadow of the state founded by Suleiman I.
Anatolia had fragmented into numerous independent Turkish principalities known as beyliks.
The central authority of the Seljuk sultan had largely disappeared.
Mesud II died around 1307–1308, with no violent cause of death recorded.
He is generally regarded as the last Seljuk ruler of Rum to retain a meaningful claim to the old Seljuk state.
Mesud III: The Final Name on the List
The final ruler was Mesud III, the son of Kayqubad III rather than Mesud II.
His reign lasted only about a year.
By this stage, the Sultanate of Rum had effectively dissolved, and independent beyliks had taken control of different parts of Anatolia.
Mesud III possessed little more than the title of sultan.
He died around 1308, although the details of his death were not recorded.
With his death, the Seljuk Sultanate of Rum disappeared from history.
From a Powerful Sultanate to the Rise of the Beyliks
When the entire succession is viewed together, an important pattern emerges.
The earliest Seljuk rulers generally faced the traditional dangers of medieval kingship: foreign armies, rival kingdoms, and battlefield defeats.
But as the dynasty progressed, the greatest danger increasingly came from within.
Brothers fought brothers.
Sons challenged fathers.
Rulers were poisoned, strangled, executed, or forced into exile.
Eventually, even the Seljuk sultans themselves no longer controlled the political system they supposedly ruled. Mongol authorities increasingly decided who could occupy the throne.
By the beginning of the 14th century, the once-powerful Sultanate of Rum had fragmented into numerous independent Turkish beyliks across Anatolia.
And among those beyliks was a relatively small frontier principality in northwestern Anatolia.
Its ruler and descendants would eventually build a state that transformed the region forever.
That principality was the Ottoman Beylik.
The Seljuk Sultanate of Rum had disappeared, but the political world it left behind would become the foundation for the rise of the Ottoman Empire.
