But this may not be the full story: given the seven-decade timeframe of Borobudur’s construction, a couple of hundred men, working when harvest cycles allowed, could have achieved a very great deal. The Sailendras in all likelihood simply called upon that traditional obligation to offer part-time labour to the overlord. Men who were used to giving a portion of their working life to building roads or roofs for the ruler, or helping in the planting of royal rice fields, found themselves deflected in the direction of the andesite quarries on the Progo River. And given the remarkably catholic approach to alien belief systems that Java has displayed over the centuries, they probably simply shrugged when presented with yet another outlandish pantheon, and got on with the business in hand.
Nowhere else in the Archipelago could have supported a project on this scale. Away to the north in Sumatra the Srivijayans might have had maritime mastery, but seated amongst the swamps they had to import much of their own rice, and they had direct rule over only a small population of traders and fishermen. They could hardly have conceived a project on the scale of Borobudur, let alone brought it into being.
The Sailendras vanished almost as abruptly as they had appeared. By the early decades of the ninth century their dynasty was in decline, and that other regal lineage, the Sanjaya, was making a comeback. The Sanjaya scion of the day, a man by the name of Rakai Pikatan, embarked on a Sailendra-slashing rampage through the rice fields, and the last Sailendra king, Balaputra, turned tail and fled to Sumatra to seek refuge with his co-religionists in Srivijaya. All that remained was the recently completed Borobudur, coated now with white plaster and glowing like a single molar in the green jaw of Java. This spectacular architectural legacy of the departed Buddhist overlords seems to have rather rankled with Rakai Pikatan. If the Sailendras could build something as remarkable as Borobudur, then so could he: to mark the Sanjaya resurgence, in 856 he ordered the building of Prambanan.
If the Buddhist interlude under the Sailendras had been an aberration in the Javanese narrative, then Borobudur itself was an anomaly in the local architectural tradition: squat and square and quite unlike anything that went before or after. The resurgent Sanjayas, however, went back to the architectural form pioneered in Dieng two centuries earlier. The Prambanan temple complex, built on the banks of the Opak River close to the spot where Rakai Pikatan had his palace, featured a trio of towering temples in the classic three-tiered Javanese style, but expanded on a monstrous scale. The central temple was 154 feet (47 metres) tall.
Over the coming half-century Central Java developed an unfettered addiction to temple building. In almost every potentially auspicious spot, every pleasing plateau or conspicuous confluence, a column of carven black stone was thrown up by the masons. The plains and hills around Prambanan are thick with these temples. Some are dedicated exclusively to Shiva; a few are given over to the Buddha. But something significant was underway at the time: Java, it seems, was chewing up and digesting these once divergent Indian traditions and turning them into something of its own—a syncretic faith in which worship of Shiva dominated, but into which a Vaishnavite thread was also woven along with all sorts of local strands, and where the Buddha was a paid-up member of the pantheon. This tradition, which first took shape in Sanjaya-ruled Mataram, is best described as ‘Hindu-Buddhism’.
They heyday of Sanjaya-ruled Mataram lasted a mere fifty years. What brought it to an end is unclear, but the unconstrained royal passion for temple building may have eventually put an unbearable strain on the old systems of labour obligation. Here and there a family might have quietly decided to strip the rattan walls of their hut, load their buffalo, and head east to a new country where there were no temple-mad kings. Such a process would only have accelerated in the third decade of the tenth century, when a massive eruption of the Merapi volcano devastated Mataram and caked the countryside with cloying grey ash. It was certainly at around that point that the elite itself decided to pack up and move out, leaving the temples to the birds and shifting the centre of royal power in Java some four hundred miles to the northeast. The move would bring an unexpected boon: the two distinct power sources that had fuelled the previous polities in the Archipelago—the maritime advantages of Srivijaya and the agricultural wealth of Mataram—were about to intersect with spectacular consequences.
The mountain rises sheer from the sweltering coastal plains of northeast Java. It is modest compared to the monsters of the interior—a mere 5,240 feet (1,600 metres). And it is long-dead: no sulphurous smoke issues from its crown and the water from its springs is icy cold. But it is perfectly formed. Its crown bursts through the blanket of forest, marked with deep grooves and catching at the running cloud, and lower down, each of its cardinal points is marked by a smaller outlying summit. Sailors passing along the channel offshore can see it even on days when the bigger peaks behind are cloaked in cloud. It is a mountain that has been catching the eye and the imagination for millennia, and there were surely sacred sites on its forested flanks long before Indian, Arabian or European traditions washed ashore here. Its name is Gunung Penanggungan.
Penanggungan is the northernmost sentinel of the Arjuno-Welirang massif, a hulk of high ground with a river basin opening on either side. To the east lies the Malang plateau, drained by the Kali Welang River and with the huge Bromo-Tengger massif rising beyond. To the west, meanwhile, a much broader river basin opens—the floodplain of the Brantas, East Java’s longest river.
It was in these basins on either side of Penanggungan that royal power reconfigured in the tenth century, and the mountain became the sacred mascot of the new realms, claimed to be the tip of the mythical Mount Mahameru, home of the Hindu pantheon, broken off when the gods transported it from India to Java. This new, volcano-guarded wellspring of history still offered all the rich returns of field and forest which had fuelled the ruling dynasties of Mataram. But the Brantas delta also emptied into a sheltered sea with safe anchorages and steady trade winds. If a single centre point of the Archipelago can be identified, then this is probably it. The region was equidistant between the Straits of Melaka and the Spice Islands of Maluku. Makassar, the major gateway to eastern waters, was an easy sail away across the Java Sea, as were the river mouths of southern Borneo.
The various kingdoms and dynasties that bubbled up on the Brantas and around the flanks of Penanggungan over the centuries were essentially reincarnations of the same polity. But with each rebirth the power grew—shipping lines crept further across the Archipelago and beyond, and new vassals were collected on far-flung shores. The capital of these East Java kingdoms was usually somewhere around the point where the Brantas splits into its delta, approachable by boat from the sea and in full view of Penanggungan. This political hub was twinned with a port at the mouth of the Kalimas distributary, the site of the modern city of Surabaya. Trade goods of all kinds passed through this harbour, but the greatest boon was spices—for nutmeg and cloves from Maluku had already become a major global commodity. Soon, East Java kings were collecting tribute from distant islands, and even beginning to challenge the Straits of Melaka as the focus of Archipelago trading power.
The first truly great king to rise out of this bubbling cauldron—and, indeed, one of the first historical figures in the Archipelago to have a character and a narrative still clearly discernible today—was a man by the name of Airlangga.
Airlangga was the son of Javanese princess called Mahendradatta and a Balinese king called Udayana. Bali was a remote and rugged place that had kept its old Austronesian traditions strong. Its own chieftains had probably had little contact with royal Java in the days when the Mataram region was the centre of the local universe. But once Javanese power had reconfigured closer at hand on the Brantas delta, the trajectories of Java and Bali had become increasingly