By the thirteenth century, Anji (local warlords) had organised their magiri (10-15 villages) into larger units which had evolved into three independent kingdoms, Hokuzan (Northern kingdom ), Chuzan (Middle Kingdom )and Nanzan (Southern Kingdom ). There is an historical account on mainland Japan that says the Ryukyuans or the people of 'Nanto' (which literally means 'southern islands') were fierce fighters and that they enjoyed fighting so much that they ate the men they vanquished. The cannibalism of course is a myth, but as to fighting, the Ryukyuans were able to turn back a Mongol invasion of 6,000 soldiers in 1291, when the main island's population was estimated to be around 20,000-30,000. Of the three kingdoms, the Chuzan was the strongest with 12 castles or guskus, the largest spanning 150 metres and the smallest just 22 metres. The next strongest kingdom was Nanzan with ten castles or guskus, the largest at 183 metres and the smallest at 49 metres in length. The least strongest Kingdom to the mountainous north (Hokuzan) possessed low yielding farmland and had two forts or guskus one at 100 metres length and the other 103 metres.

Each kingdom maintained city-states that developed and enjoyed trading privileges with various countries in the Asia Pacific Region. Principal returning cargoes were sappanwood and pepper. Sappanwood sold in China for 100 times the prevailing price in the Ryukyus and pepper from 750-1500 times the price in South East Asia. Other goods brought from South East Asia included cloves, nutmeg, camphor, gold, tin, ivory, sandalwood, perfumes and incense, coral, mercury, opium, saffron, Malacca wine, cotton prints, muslin, silk goods, olibanum, eaglewood, costusroot, ebony, agate and exotic animals and birds. From archaeological evidence, the most popular imported items from China amongst Ryukyuans were celadons (porcelain) from the province of Zhejiang. In 1373 with the threat of Mongols to their northern boarders, Ming Dynasty China took great interest in trade with the Ryukyus, creating a demand for Ryukyuan horses and sulphur (from Kume Island, used to produce gunpowder).
In 1416, Sho Hashi King of Chuzan started on a military campaign against the King of Hokuzan, Hanan Chi. With a force of 2,800 soldiers, the armies of Chuzan managed to capture the capital of the north- Nakijin and bring the two Kingdoms together. In 1429, Sho Hashi turned his eye southward and de-throned King Taro Mai of Nanzan, thereby unifying the main island and creating the Ryukyu Kingdom.

The Golden Age of the Ryukyus is said to have been between 1385 and 1570, when the country was strong enough and rich enough to maintain central authority and to eventually put a ban on the private possession of weapons. At this time karate became a popular means of settling scores, developed from a mixture of a local fighting style and chinese sholin kung fu. There are accounts of Chinese as well as Arabs, Koreans, and Japanese living in Naha during the Golden Era of Trade. There were 36 Chinese families recorded in Kumeson, a district of Naha during this time, sent as emissaries by the Ming Dynasty. While the cities flourished with parks and temples, farmers out in the countryside were still expected to pay the same tribute to the royal courts, and subsequently there were a number of rebellions. The Yaeyama Islands to the south rebelled against Shuri in 1496, in response to which King Sho Shin dispatched nine generals and 3,000 soldiers in 46 ships to crush the rebellion in 1500. Thirty-seven years later a farmer's rebellion to the north on Amami Oshima was also ruthlessly crushed.
The Ryukyuans began loosing their trading influence to the south with the appearance of Portuguese trade ships in the Asia Pacific Region. Armed with canon and shot, Portuguese ships (man of wars) made quick work of lightly armored Ryukyuan trading ships. With the capture of Malacca in 1511, the Portuguese under the command of Albuquerque monopolized trade in South East Asia, pushing the Ryukyuans out of ports in Siam, Palembang, Java, Sumatra, Patami, Armam and Sunda. After 1520 Ryukyuan ships traded with Siam and Patami only and by 1541 they maintained trade with only Siam. The Portuguese were also to share the same fate that they had dealt to Ryukyuan trade ships with the arrival of the Dutch East India Company in South East Asia. Armed with long-range canons, the Dutch could pick off the heavily gunned Portuguese ships at a distance.
To the north Japanese pirates (wako) who had been raiding Korea and China began moving southwards. Early in the fourteenth century their targets were mainly the Korean coastline, gradually moving down the coast to southern China along Fukien and Hangehou. After the civil war of Onin (1467-1477), when the power of the Ashikaga Shogunate in Kyoto became too weak to control resistive feudal lords, more pirates menaced Ryukyu shipping to the north. In 1480 Ryukyuan trade ships withdrew from Hyogo and Sakai, even though Sakai merchants still ventured to Naha through dangerous waters controlled by the Satsuma clan. There were two failed attempts by Japanese feudal lords to take over the Ryukyu Islands in 1516 and 1591 along with several attacks by pirates. The last King of an independent Ryukyu Kingdom, King Sho Nei came to the throne in 1589, managed to suppress a rebellion of the Jana clan in Naha three years later, but was completely helpless when in 1609 the Satsuma clan invaded with 3,000 soldiers and 1,000 ships. He was taken hostage to Japan and returned to the Ryukyus two years later, a mere vassal of the Satsuma clans of Kagoshima.
P. Saeki