Narathihapate (Burmese: နရသီဟပတေ့, pronounced [nəɹa̰ θìha̰pətḛ]; also Sithu IV of Pagan; 23 April 1238 – 1 July 1287) was the last king of the Pagan Empire who reigned from 1256 to 1287. The king is known in Burmese history as the "Taruk-Pyay Min" ("the King who fled from the Taruks") for his flight from Pagan (Bagan) to Lower Burma in 1285 during the first Mongol invasion (1277–87) of the kingdom. He eventually submitted to Kublai Khan, founder of the Yuan dynasty in January 1287 in exchange for a Mongol withdrawal from northern Burma. But when the king was assassinated six months later by his son Thihathu, the Viceroy of Prome, the 250-year-old Pagan Empire broke apart into multiple petty states. The political fragmentation of the Irrawaddy valley and its periphery would last for another 250 years until the mid-16th century.

The king is unkindly remembered in the royal chronicles, which in addition to calling a cowardly king who fled from the invaders, also call him "an ogre" and "glutton" who was "great in wrath, haughtiness and envy, exceeding covetous and ambitious." According to scholarship, he was certainly an ineffective ruler but unfairly scapegoated by the chronicles for the fall of the empire, whose decline predated his reign, and in fact had been "more prolonged and agonized".

The future king was born to Crown Prince Uzana and a commoner concubine from Myittha on 23 April 1238. For much of his early years, he was known at the palace as Min Khwe-Chi (lit. "Prince Dog's Dung") as a harmless royal. Even when his father became king in 1251, Khwe-Chi was not in line for the throne; the position belonged to his half-brother Thihathu, the eldest son of the chief queen Thonlula.

But fate came calling. In early May 1256, Uzana died from a hunting accident, and Thihathu claimed the throne. The court led by the powerful chief minister Yazathingyan did not accept a head-strong Thihathu, and placed their preferred candidate, Khwe Chi, whom they believed they could control, on the throne on 6 May 1256. Thihathu was arrested and executed. Narathihapate held the coronation ceremony in November 1256. He assumed the regnal name "Śrī Tribhuvanādityapavara Dhammarāja" (ၐြီတြိဘုဝနာဒိတျပဝရဓမ္မရာဇ).

The young king turned out be quick-tempered, arrogant, and ruthless. Soon after his accession, he sent Yazathingyan, the man who put him on the throne, into exile. But he soon had to recall Yazathingyan to quell the rebellions in Martaban (Mottama) (1258–1259) and Arakan (1258–1260). Yazathingyan put down the rebellions but died on the return journey. With the old minister's death removed the only person that could have controlled the ruthless, inexperienced king.

Narathihapate was incompetent in both domestic and foreign affairs. Like his father and grandfather before him, he too failed to fix the depleted royal treasury, which had been deteriorating for years because the continued growth of tax-free religious landholdings. But unlike his grandfather Kyaswa, who would rather build a small temple than to resort to forced labor, Narathihapate built a lavish temple, the Mingalazedi Pagoda with forced labor. The people, sinking under his rule, whispered: "When the pagoda is finished, the king shall die".

The existential threat to the Burmese kingdom came from the north. The Mongols, who conquered the Dali Kingdom (later renamed as Yunnan in 1274) in 1253–57, first demanded tribute from Pagan in 1271–72. When the Burmese king refused, Emperor Kublai Khan himself sent a mission in 1273 to demand tribute once again. The king refused again. The Mongol army of the Yuan dynasty in 1275–76 consolidated the Pagan–Yunnan borderlands as part of their drive to close off escape routes of the Song refugees, and in the process went on to occupy a Burmese vassal state in present-day Dehong Prefecture). Narathihapate sent the army to reclaim the region but the army was driven back in April 1277 at the battle of Ngasaunggyan (modern Yingjiang). The Mongol troops reached as far south as Kaungsin, which guarded the Bhamo Pass, the gateway into the Irrawaddy, before retreating in 1278 due to excessive heat. Later in 1278, the army reestablished its forts at Kaungsin and Ngasaunggyan.

Narathihapate's troubles were not over. In 1281, the Mongol emperor again demanded tribute. When the king refused, the emperor ordered an invasion of northern Burma. In September 1283, the Mongol forces again attacked the Burmese fort at Ngasaunggyan, which fell on 3 December 1283. Kaungsin fell six days later, and the Mongols took Tagaung on 5 February 1284. But the Mongols found the heat excessive and retreated from Tagaung. The Burmese forces retook Tagaung on 10 May 1284. The Mongol resumed their drive southward in the following dry season (1284–85), and reached as far south as Hanlin by February 1285. Although the Mongols did not have the order to attack Pagan, the king nonetheless fled south to Lower Burma.