How do you define successful?

Also, the unified Mongol Empire that spanned much of Eurasia broke apart after the death of Mongke. Although Khublai was nominally acknowledged as Great Khan, the four khanates by then were, for all intents and purposes, completely autonomous and independent political entities. In fact, Khubilai's claim was not even acknowledged by all of the Mongols. Throughout his reign and that of his successors', there were repeated attempts by Khaidu and others from the House of Ogodei to challenge him.