Chapter 1 - The Japanese Invasion of Luzon
The Japanese Invasion of LuzonThe Matsukara conspiracy almost died in a bath. Quite literally, a naked Matsukara Shigemasa was attacked in his bath by masked assassins before his spies could report back on the fortifications of Manila and Luzon. However, he was able to beat one of the assassins so hard in the face with a bath implement, the attacker slipped, hit his head on a rock, and fell into the bath and drowned. The confusion gave Matsukara enough time to escape the bath, aware that he had domestic enemies. After holing himself protected by bodyguards 24/7, this attempt only strengthened Matsukara's conspiracy. Most modern historians suggest that the Tokugawa Shogun attempted to assassinate him, correctly fearing that his brutal oppression of peasants would eventually lead to a revolt. However, Matsukara's behavior continued. After all, he needed to extract every single grain of rice from his subjects in order to further his grandeur - ruling over a vast empire. As a daimyo of the Shimabara Domain in Kyushu, Matsukara was actually more familiar than most with the dynamics of the different Nanban ("Southern Barbarians") - he was in particular a virulent opponent of Roman Catholicism and was aware that the Dutch barbarians followed a slightly different form of Christianity than that espoused by the Jesuits he so loathed. All of these considerations played into his plan of conquest.
Coming into contact with members of the Dutch East India Company ("VOC") in their nearby trading post in Hirado, his conspiracy soon became complete. The VOC was currently locked in a colonial war with the Portuguese (who were in personal union with Spain), in hopes of trying to take over all of Portugal's possessions in Asia and gain control of the Spice Trade. However, the VOC lacked in resources and their previous attempts to ply other rulers, such as the Khmer and Ayuthayya Empires, had failed. In Matsukara, they found a remarkably agreeable local warlord. Matsukara promised that if given Dutch transportation and logistic support, he could muster 6,000 troops, about 4,000 Ashigaru spearmen/archers and 2,000 rifleman (both samurai and non-samurai). Matsukara was aware that the bakufu government in Edo would strongly disapprove of this, but he was aware that if he triumphed and ruled over a large territory (the so-called "Philippines), he would be one of the most powerful daimyo of the realm. Under the deal, the Dutch would transport his troops to Manila, where they would destroy the entire Spanish garrison and then take control of all of Luzon. The Dutch would then continue to support Matsukara as he moved to take control of Cebu. Matsukara saw this as a huge opportunity, but so did the Dutch. They were aware any attack on the Spanish Philippines would redirect effort and attention from the Iberian defense of the rest of their possessions, including in the East Indies, Goa, and Macau. In addition, the VOC knew that any strike against Spanish possessions would be viewed favorably back in the Netherlands, due to the on-going War for Dutch Independence. The Spanish were vaguely aware that such a situation was going to occur thanks to their intelligence network being far superior to Matsukara's.
In early 1632, the Dutch-Shimabara force sailed from Kyuushu. Matsukara Shigemasa put his son, Matsukara Katsuie in charge of the Shimabara Domain. Upon landing in Manila, the Spanish were remarkably well-prepared and had set defensive positions throughout all of Manila. However, there was a huge numerical disparity. The Shimabara forces had over 6,000 troops to only 1,000 Spanish troops, who were severely outmatched in firepower due to the support of Dutch artillery and naval forces. Spanish forces bravely resisted, throwing back repeated assaults and inflicting two or three losses for every Spaniard lost despite their inferiority in training and tactics. However, the walls of Manila ultimately came down, and Shigemasa ordered the brutal execution of every last Spaniard in Manila, skewering them on pikes and leaving their rotting bodies outside the walls of Manila. Disturbingly to the Dutch, this included the families and servants of all the fallen Spaniards as well as any Spanish/Portuguese merchant families found in the city. Almost all of the residents of the Spanish town of Intramuros were butchered, with all of the silver seized by Matsukara to pay off the nearby Wokou pirates into neutrality (which they quickly interpreted to mean open season on Spanish ships). With almost no Spanish forces left in Luzon and a remarkably disturbing display of his brutality, the small towns that had paid fealty/tribute to the Spanish quickly fell into line, paying fealty instead to Matsukara. The brave sacrifice of the Spanish troops dealt enough damage to Matsukara's Army that he put off the assault on Cebu (due to insufficient men), focusing instead of brutally suppressing resistance in Luzon, rebuilding his army, and sending a smaller force to besiege Cebu. Matsukara's reign in Luzon became increasingly erratic and bloody though, as he extorted and murdered local tribes and peasants to fund future conquests. Across the Pacific, Dutch forces prepared to assault additional Portuguese colonial outposts.
The reaction in Edo was horror. The Tokugawa Shogunate was aware of the power and wealth of the Spanish Empire and was primarily concerned at maintaining stability at costs. Shogun Tokugawa Iemitsu dismissed all of his regents in 1632 that were sent by his father to restrain the cunning, but violent young Shogun, blaming them for being incompetent and unable to restrain Matsukara. They resented the accusation and when Iemitsu ordered his brother, Tadanaga, to commit suicide, one of them even broke into Tokugawa Tadanaga's house, helping his brother escape. Although deploring the war, Iemitsu was pressured by almost all of the daimyo who feted the "triumphant Matsukara" to award him Luzon as part of the Shimbara Domain. Iemitsu grew to distrust the Dutch however just as much as he distrusted the Spanish/Portuguese. Although Iemitsu was not opposed to brutality, he suspected Matsukara's brutality in Manila would spark a reaction from the Spanish home country. He was right.
The loss of silver galleons proved a brutal financial blow to the Spanish Empire in 1632, already reeling in various wars, including wars with the Netherland, England, France, and the entire Thirty Years War. Silver imports were significantly down from New World, and Dutch fleets in Manila made it much harder to sneak treasure fleets from China to Mexico. When reports of the massacre at Manila reached Spain, the entire court reacted in anger, both at the lost revenue and the brutal massacre of innocents. Anger was especially directed at the Netherlands, as the court under the lead of Foreign Minister Olivares had largely adopted a "Netherlands first" strategy in the various wars at the time. Spain had literally declared state bankruptcy in 1627 in order to try to restore its financials, and it just took another gruesome hit. In order to prevent a state bankruptcy, Olivares had concluded something had to be done. Spain might not have the manpower necessary to secure Manila, but they could certainly try to protect Cebu and the other Portuguese colonies. However, there was great disagreement in how to accomplish this.
Simply put, the interests of Spanish and Portuguese nobles were at odds with each other. The Spanish wanted to retain the China ->Mexico-> Spain trade. However, the Portuguese were in complete disagreement - they believed the most important route was China -> East Indies -> Indian Ocean -> Around the Cape -> Portugal. A decision was made that seemed fair, but which still angered the Portuguese - Spanish fleets in Pacific New Spain would sail to Acapulco and attack Manila. After all, Manila and the Spanish East Indies were part of New Spain, and it seemed natural for large amounts of troops to be directed from New Spain to another part of New Spain. At the same time, Portuguese fleets and troops would be diverted from the Indian Ocean and East Indies to interdict the Dutch. The plan was for the Portuguese fleet to help Cebu hold out, before Spanish armies from Mexico could arrive and retake Manila, perhaps even launch an expeditionary attack on Japan itself to punish the Japanese. There was a clear risk that the Ottomans or Safavid Empires would take advantage of such an absence (the time it took reinforcements from Portugal/Spain to re-guard the Indian ocean), but quite frankly, Olivares didn't care. He prioritized the Manila Galleon trade, which directly enriched the Castillian monarchy, over the Spice Trade, which largely only enriched Portuguese nobility. Enriching the center at the expense of the periphery would presumably actually aid in his centralization and reform drive. The Spanish court voted to implement this plan over the objection of Portuguese nobles.
 OTL, Matsukara was assassinated here in 1630 because the central government wanted to stop him. But this time, he escapes.
 OTL, his brother was killed.