The founder of the Majapahit Empire, Kertarajasa, was the son-in-law of the ruler of the Singhasari kingdom, also based in Java. After Singhasari drove Srivijaya out of Java in 1290, the rising power of Singhasari came to the attention of Kublai Khan in China and he sent emissaries demanding tribute. Kertanagara, ruler of the Singhasari kingdom, refused to pay tribute and the Khan sent a punitive expedition which arrived off the coast of Java in 1293. By that time, a rebel from Kediri, Jayakatwang, had killed Kertanagara. The Majapahit founder allied himself with the Mongols against Jayakatwang and, once the Singhasari kingdom was destroyed, turned and forced his Mongol allies to withdraw in confusion. Gajah Mada, an ambitious Majapahit prime minister and regent from 1331 to 1364, extended the empire's rule to the surrounding islands. A few years after Gajah Mada's death, the Majapahit navy captured Palembang, putting an end to the Srivijayan kingdom. Although the Majapahit rulers extended their power over other islands and destroyed neighbouring kingdoms, their focus seems to have been on controlling and gaining a larger share of the commercial trade that passed through the archipelago. About the time Majapahit was founded, Muslim traders and proselytisers began entering the area. After its peak in the 14th century, Majapahit power began to decline and was unable to control the rising power of the Sultanate of Malacca. Dates for the end of the Majapahit Empire range from 1478 to 1520. A large number of courtiers, artisans, priests, and members of the royal family moved east to the island of Bali at the end of Majapahit power. The earliest accounts of the Indonesian archipelago date from the Abbasid Caliphate, according to those early accounts the Indonesian archipelago were famous among early Muslim sailors mainly due to its abundance of precious spice trade commodities such as nutmeg, cloves, galangal and many other spices. Although Muslim traders first travelled through South East Asia early in the Islamic era, the spread of Islam among the inhabitants of the Indonesian archipelago dates to the 13th century in northern Sumatra. Although it is known that the spread of Islam began in the west of the archipelago, the fragmentary evidence does not suggest a rolling wave of conversion through adjacent areas; rather, it suggests the process was complicated and slow.