Castilian War

Since the middle of the 16th century, Europeans had been eager to gain a foothold in Southeast Asia, the source of supply for spices. Spain also wanted to forcibly spread the acceptance of Christianity, the overwhelmingly dominant faith in Europe. After the Fall of Constantinople in 1453, the land routes from the Eastern Mediterranean to Southeast Asia through Central Asia and the Middle East were controlled by the Ottomans, Persians, Arabs, Indians, and the Malays.

The Portuguese, and later the Spaniards, tried to find an alternative route by sea to Southeast Asia, so they could trade in spices and other products with the Malays. The Portuguese in particular did this by conquering Malacca in 1511, two years after their arrival in the region.

The Spaniards arrived later, in the mid-16th century. Their arrival to the archipelago now part of the modern-day Philippines, as well as Spain's intention to spread Christianity, caused a conflict with Brunei, then ruled by Sultan Saiful Rijal, which eventually led to the Castilian War. At the time, Brunei Darussalam was a powerful maritime empire extending from Borneo Island to most of the Philippines.

From their ports in Mexico, Spain sent several expeditions to the Philippines and in 1565, under Miguel López de Legazpi, settled in Cebu. For a time, Cebu became the capital of the archipelago and the main trading post. It was also the first city to spreading Christianity in the islands.

Because of this, the Spanish aspirations came to clash with those of Brunei. Between 1485 and 1521, the Sultanate of Brunei led by Sultan Bolkiah had established the state of Kota Serudong (otherwise known as the Kingdom of Maynila) as a Bruneian puppet state opposed to the local Kingdom of Tondo.[3] Islam was further strengthened by the arrival to the Philippines of traders and proselytisers from present-day Malaysia and Indonesia.[4]

Despite the influence of Brunei, the multiple states that existed in the Philippines simplified Spanish colonisation. In 1571, Miguel López de Legazpi attacked and Christianised Islamic Manila, which became the capital of the Philippine Islands, also becoming a hub for trade and evangelisation. The Visayans, (people from the Kedatuan of Madja-as and Rajahnate of Cebu) which before the Spaniards came, had waged war against the Sultanate of Sulu and the Kingdom of Maynila, now became allies of the Spaniards against the Sultanate of Brunei.

The time the Castilian War broke out was a time of religious fervor in Europe and many parts of the world, when a single state religion was followed. In Spain, the state religion was Roman Catholicism, obliging followers of other faiths such as Jews and Muslims to convert to this religion. Spain had recently finished a 700-year-old war to reconquer and re-Christianise Spain, which had been invaded by the Muslims under the Umayyad Caliphate since the 8th century AD. The long process of reconquest, sometimes through treaties, mostly through war, is known as the Reconquista. The hatred of Spaniards against the Muslims that once invaded Spain fuelled the Castilian War against the similarly Muslim Bruneians. This war also started the Spanish–Moro Wars in the Philippines against the Sultanate of Sulu and Sultanate of Maguindanao.

In 1576, the Spanish Governor in Manila, Francisco de Sande, had arrived from Mexico. He sent an official mission to neighbouring Brunei to meet Sultan Saiful Rijal. He explained to the Sultan that they wanted to have good relations with Brunei and also asked for permission to spread Roman Catholicism in Brunei. At the same time, he demanded an end to Brunei proselytism of Islam in the Philippines. Sultan Saiful Rijal would not agree to these terms and also expressed his opposition to the evangelisation of the Philippines, which he deemed part of Dar al-Islam. In reality, de Sande regarded Brunei as a threat to the Spanish presence in the region, claiming that "the Moros from Borneo preach the doctrine of Mohammed, converting all the Moros of the islands".[5][6]

Spain declared war in 1578. In March that year, the Spanish fleet, led by de Sande himself, acting as Capitán General, started their journey towards Brunei. The expedition consisted of 200 Spaniards and 200 Mexicans, 1,500 native Filipinos (Luzones), and 300 Borneans.[7] The campaign was one of many, which also included action in Mindanao and Sulu.[8][9] The racial make-up of the Christian side was likely diverse, as documents a few decades later showed that the infantry was composed of mestizos, mulattoes, and "Indians" (From Peru and Mexico), led by Spanish officers who had worked together with native Filipinos in military campaigns across Southeast Asia.[10] The Muslim side though was also equally racially diverse. In addition to the native Malay warriors, the Ottomans had repeatedly sent military expeditions to nearby Aceh. The expeditions were composed mainly of Turks, Egyptians, Swahilis, Somalis, Sindhis, Gujaratis, and Malabars.[11] These expeditionary forces had also spread to other nearby Sultanates such as Brunei and had taught local mujahideen new fighting tactics and techniques to forge cannons.[12] Muslim migration from the Ottoman Caliphate, Egypt, Mecca and Arabia was so constant that Melchor Davalos complained to the Spanish King of their presence in Borneo and the Philippines.

Persians and Arabs and Egyptians and Turks brought [Muhammad's] veneration and evil sect here, and even Moors from Tunis and Granada came here, sometimes in the armadas of Campson [Kait Bey], former Sultan of Cairo and King of Egypt... Thus it seems to me that these Moros of the Philippine Islands [are] mainly those who, as had been said, come from Egypt and Arabia and Mecca, and are their relatives, disciples and members, and every year they say that Turks come to Sumatra and Borneo, and to Ternate, where there are now some of those defeated in the famous battle which Señor Don Juan de Austria won.

— Melchor Davalos

The fighting was fierce, but Spain succeeded in invading the capital of Brunei at that time, Kota Batu, on 16 April 1578, with the help of two disgruntled Brunei noblemen, Pengiran Seri Lela and Pengiran Seri Ratna. The former had travelled to Manila to offer Brunei as a tributary of Spain for help to recover the throne from his brother, Saiful Rijal.[13] Spain agreed that if they succeeded in conquering Brunei, Pengiran Seri Lela would indeed become the Sultan, while Pengiran Seri Ratna would be the new Bendahara.

Sultan Saiful Rijal and Paduka Seri Begawan Sultan Abdul Kahar were forced to flee to Meragang, then to Jerudong, where they made plans to chase the conquering army from Brunei. In the meantime Spanish were greatly weakened by heavy losses due to an outbreak of cholera or dysentery.[14][15]

Since they were outnumbered and outgunned, this victory entered into Brunei Darussalam's national conscience as a heroic episode, with the Spaniards and their allies being driven out by Pengiran Bendahara Sakam Ibni Sultan Abdul Kahar with a thousand native warriors to restore the Sultan's power over the Empire. The Spanish returned to Manila on 26 June 1578, after just 72 days. Before doing so, they burned the mosque, a high structure with a five-tier roof.

Pengiran Seri Lela died in August/September 1578, probably from the same illness that had afflicted his Spanish allies.

Notwithstanding their retreat from Brunei, Spain managed to keep Brunei from regaining a foothold in Luzon.[16] A few years later, relations improved and Spain began trading with the Sultanate, as evidenced by a letter from Don Francisco de Tello de Guzmán, Governor General of Manila, dated 1599 asking for a return of normal relationship.[17] The end of the Castilian War also allowed Spain to focus its attention on the Spanish-Moro war.

The Sultanate of Brunei would cease to be an empire at sea, eventually turning into a city-state, setting aside any previous territorial expansion policies, and had to give the territory to James Brooke because of riots in Brunei territory.

It became one of the smallest nations in the world today. Its new policy of sustained caution in its dealings with European powers allowed it to survive and become the oldest continuously Islamic political state.[18]