The Dutch arrived in southern Formosa in 1624 and built Fort Zeelandia on the sandy peninsula of Tayouan. Their original plan was modest: run a trading post, not a colony. But the fortress needed food, and supply ships from the colonial headquarters in Batavia arrived irregularly and at great expense. The company allied with Sinkan, the nearest aboriginal village, which supplied firewood, venison, and fish. That alliance came at a cost. The aboriginal settlements of the southwest were locked in perpetual low-level warfare with one another, raiding for heads and plunder, and friendship with Sinkan put the Dutch squarely in the crosshairs of its enemies. Between 1625 and 1629, a series of skirmishes, failed pirate raids, and shifting loyalties eroded the Dutch position. The Sinkan villagers, frustrated by Dutch weakness, even sent a delegation to Japan to seek the protection of the shogun Tokugawa Iemitsu. He refused them an audience, but the gesture underscored how little the VOC was trusted.

The garrison at Fort Zeelandia counted just 400 men, only 210 of them soldiers. Governor Hans Putmans begged Batavia for reinforcements, and in 1635, 475 soldiers finally arrived with orders to avenge the 1629 massacre and establish real authority. Providence seemed to favor the Dutch: smallpox ravaged Mattau and Soulang while sparing Sinkan, a sign the colonists interpreted as divine endorsement. On November 22, 1635, the reinforced army marched toward Mattau. Learning the villagers planned to flee, Putmans pushed forward and surprised them at dusk. The Dutch subdued the village without a pitched battle, then summarily executed twenty-six men and burned the houses. On the return march, they stopped at Bakloan, Sinkan, and Sakam, warning each chief of the consequences of defiance. Soulang sent two emissaries offering a spear and hatchet as symbols of alliance. Even chiefs from Mattau arrived to kneel before Dutch officials and sue for peace.

Putmans was not finished. He turned his soldiers on Taccariang, a village that had killed both VOC employees and Sinkan villagers. The Taccariang warriors exchanged blows with Sinkan scouts serving as the vanguard, but a volley of musket fire sent them running. The Dutch burned Taccariang to the ground. Next came Soulang, where warriors who had participated in the 1629 massacre were arrested and their homes torched. The last stop was Tevorang, which had sheltered fugitives from other villages. Here the governor switched tactics, offering gifts and assurances of friendship while leaving the threat of force unspoken. The Tevorangans understood. They submitted without resistance. As news of these events spread, villages the Dutch had never contacted sent delegations to Fort Zeelandia, surrendering sovereignty by presenting small trees planted in earth from their homeland. Representatives arrived from as far as Pangsoia, a hundred kilometers to the south.

On February 22, 1636, the Dutch convened a landdag, a grand assembly, at Tayouan. Twenty-eight villages from southern and central Formosa sent representatives. Governor Putmans presented the chiefs with robes and staffs of office to symbolize their new status. The missionary Robert Junius, who had helped lead the campaign, wrote that it was delightful to see the friendliness of these people when they met for the first time, to notice how they kissed each other and gazed at one another, something never before witnessed on the island, where one tribe was nearly always at war with another. The Dutch christened their new domain the Verenigde Dorpen, the United Villages, a deliberate echo of the United Provinces of their homeland. What had been a vulnerable trading post now commanded southwestern Formosa. The expanded territory gave the VOC access to the lucrative deer trade, fertile farmland worked by Chinese laborers, and aboriginal warriors who would fight alongside the Dutch in future conflicts. The pacification campaign of 1635 became the foundation on which Dutch Formosa was built.

The pax Hollandica did not last forever. Aboriginal villages rebelled against Dutch oppression in the 1650s, provoked by demands for women, deer pelts, and rice. In December 1652, warriors in the Taipei basin beheaded two Dutch translators at Wu-lao-wan, and thirty aboriginals died in the fighting that followed. An embargo on salt and iron forced the village to capitulate by February 1653, but the resentment never truly subsided. And the greatest threat came not from the villages but from the sea. In 1661, Koxinga arrived with 25,000 soldiers and drove the Dutch from Formosa entirely, ending thirty-eight years of colonial rule. The United Villages, the grand assembly, the staffs of office all passed into history. What remained was the pattern the campaign had established: the idea that southwestern Taiwan could be unified under a single power, and the knowledge that such unity came at a steep human cost.