The reino or native kingdom of Manufahi  lay on the southern coast of Timor, within the military district of Alas, based on the rationalised re-districting of 1860. It had an estimated population of 42,000 living in 6,500 houses in 1903. It owed a finta  to the Portuguese treasury of 96,000 Mexican dollars, although this was difficult to collect. It was governed by a king or liurai  who was confirmed in his position by the Portuguese governor. Manufahi's agriculturalists produced horses, sheep, cereals, fruit, coffee and tobacco. Its craftsmen were the finest silver and goldsmiths in Portuguese Timor, manufacturing bracelets and anklets. There were also skilled pyrographers working bamboo pipes. More ominously, Manufahi produced leather cartridge belts and musket shot, materials that could be put to use in a revolt. The countrywide conflict of 1911-12 was the culmination of a series of revolts led by Manufahi. The first, which took place during the reign of Dom Duarte, Boaventura's father, lasted from 1894 to 1901 and the second from 1907 to 1908. The west and north of Manufahi was the reino of Suru, centred on the mountain of Tatamailau. It had only been subdued by the Portuguese and subjugated to the reino of Atsabe in 1900. In 1907, the liurai of Suru, Naicau, petitioned the Portuguese for independence from Atsabe and it was granted. Naicau would prove loyal to the Portuguese and a thorn in Manufahi's side.
Question: How many years did the reign of Dom Duarte last?
Answer: 7