The Kathmandu Valley may have been inhabited as early as 300 BCE, since the oldest known objects in the valley date to a few hundred years BCE. The earliest known inscription is dated 185 CE. The oldest firmly dated building in the earthquake-prone valley is over 2,000 years old. Four stupas around the city of Patan that are said to have been erected by a Charumati, a purported daughter of the Maurya emperor Ashoka, in the third century BCE, attest to the ancient history present within the valley. As with the tales of the Buddha's visit, there is no evidence supporting Ashok's visit, but the stupas probably date to that century. The Licchavis, whose earliest inscriptions date to 464, were the next rulers of the valley and had close ties with the Gupta Empire of India. The Mallas ruled the Kathmandu Valley and the surrounding area from the 12th until the 18th century CE, when the Shah dynasty of the Gorkha Kingdom under Prithvi Narayan Shah conquered the valley as he created present-day Nepal. His victory in the Battle of Kirtipur was the beginning of his conquest of the valley. The Newars are the indigenous inhabitants and the creators of the historic civilization of the valley. Their language is today known as Nepal Bhasa. They are understood to be the descendants of the various ethnic and racial groups that have inhabited and ruled the valley in the two-millennium history of the place. Scholars have also described the Newars as a nation. They have developed a division of labour and a sophisticated urban civilization not seen elsewhere in the Himalayan foothills. They are known for their contributions to art, sculpture, architecture, culture, literature, music, industry, trade, agriculture and cuisine, and left their mark on the art of Central Asia. Newa architecture consists of the pagoda, stupa, shikhara, chaitya and other styles. The valley's trademark is the multiple-roofed pagoda which may have originated in this area and spread to India, China, Indochina and Japan. The most famous artisan who influenced stylistic developments in China and Tibet was Araniko, a Newar who traveled to the court of Kublai Khan in the 13th century AD. He is known for building the white stupa at the Miaoying Temple in Beijing. At present, people from other parts of Nepal tend to migrate to the valley for a better life due to its high level of cultural and economic development.