Given such flawed beginnings, it is surprising that Kashyapa, father-killer that he was, enjoyed a reign that lasted as long as it did – from 473 to 495 CE. Having completed the bizarre brickwork that turned his father into a building by walling him up, Kashyapa’s reaction to the patricide that had left him reviled by subjects and priests alike was not dissimilar to that of the Roman Emperor Tiberius, who forsook his capital for a palace of pleasure he built on Capri. Similar – but not equal, for the new seat of government he built at Sigiriya was in every way grander, more beautiful, and more advanced than was Tiberius’ Villa Jovis.

The move was no mere residential relocation. It was not just a new palace that Kashyapa built, but a new seat of government. In this, he acted far more like Akhenaten, the heretical Egyptian pharaoh of the 18th Dynasty, who moved his capital from Thebes to the purpose-built city of Akhenaten – or Amarna. The pharaoh was to die with suspicious normality, and his son, Tutankhamun, wasted little time in swiftly moving the capital back to Thebes, a pattern that was to haunt both Kashyapa and his sibling successor, Moggallana.

Hints of the long-lost forces that impelled and inspired such actions are now almost entirely lost. Although Kashyapa gained his crown by the simple expedient of murdering his father, Dhatusena, it is more than likely that he was largely put up to it by his brother-in-law, the General Migara. Migara had been instrumental in placing Dhatusena on the throne decades earlier but had fallen out badly with his father-in-law when the king murdered the general’s wife, who, as was the way with things then, was also the king’s sister. Sri Lankan politics, then, as now, is rarely straightforward, but this moment of homespun realpolitik set such new standards for utter complexity that they are still to be bettered today.

Undoubtedly, these family squabbles would have fed off all that was going on in the kingdom at the time. And there was a lot else going on. Under Dhatusena, Anduraupura had been turned on its head, the once inward-looking city now humming with foreigners, most of whom had come to either trade or convert. Arabs, Jews, Europeans, and Indians are just some of the groups known to have taken exuberant root in the city, as it opened itself up once more to the bountiful trade and money brought to Sri Lanka by the Maritime Silk Road – that vast maritime network of the ancient world that linked East Africa, Arabia, India, and China to Europe. The kingdom was enjoying a moment of money-spinning madness, with riches pouring into the land as never before, transforming life much as the railroads did in 19th-century America. With trade came new forms of religion – Christianity, for example, and – much more threateningly – alternative schools of Buddhism that Sri Lanka’s overwhelmingly and all-powerful Theravada Buddhists saw as blatantly heretical. Conversions this way or that, as well as making and spending money, were the new order of play.

General Migara is thought to have leveraged these nascent forces to empower himself, but his alliance with Kashyapa came under pressure. The new king did not see himself as the leader of a Liberation revolution, however much he tolerated it for its money-making powers.

Kashyapa’s preference was for crafting a much more traditional and politically useful personal reputation – as a Buddhist God-king. An intriguing hint of this artful propaganda was discovered in a contemporary rock inscription in the monastery of Thimbiriwewa. The inscription noted a donation given “in the tenth year of the raising of the umbrella of dominion by the Great King Kashyapa, the Lord of Alaka.” Alaka is a reference to the God Kuvera, the legendary ruler of mythical Lanka. Traditional Buddhists were familiar with this blending of god with king, a fusion that did much to legitimise government. If kings were gods, or as good as, what right did any subject, might or meagre, have to obstruct them? It was not in Kashyapa’s interests to do anything to imperil the traditional way in which his people regard kingship. Indeed, he is known to come very actively to the assistance of Theravada Buddhists when General Migara sought to emasculate them by favouring rival Buddhist schools whose attitudes to kingship were perhaps a little looser.

But Kashyapa’s predilection for the expediencies of traditional religion was not always returned by grateful monks, many of whom, thinking it unsuitable for a king to have killed his own father, viewed him as well beyond the pale. One monastery is even known to have refused his offer of donations, branding him a father-killer. With his old capital, Anduraupura, a seething pit of viperous power politics, and religion itself too often an uncertain alley, what better plan than to start anew at Sigiriya. Of money, there was no shortage, so building a better future elsewhere was well within his powers. But did he?

Kashyapa's reign lasted little more than 20 years, and it is a mathematical impossibility that in so short a time, so celebrated a place as Sigiriya could ever have been started, let alone finished. Indeed, it is unlikely that the previous king, Dhatusena, even established the city fortress. Modern historians are instead converging on the view that the site was begun much earlier, in 341 CE, by the Lambakanna king, Buddhadasa, a ruler so beloved that the Mahavamsa Chronicle has him down as a "Mind of Virtue and an Ocean of Gems".

Archaeologists have discovered building periods in and around the site that point to earlier dates, though they have also noted how, over the Kashyapa years, the plans become monumentally more ambitious. Until more research is done, hunches, probabilities, and guesswork are the ephemeral friends of choice for concluding that Kashyapa, in moving to Sigiriya, relocated to an existing site and then set about radically improving it, not unlike Louis XIV at Versailles.

But such caveats aside, Kashyapa’s Sigiriya was nevertheless one of the greatest wonders of Ancient Asia. It set imposing new standards for urban planning, the royal bastion surrounded by an elaborately laid out outer city, with a final circle of three types of gardens around it: water, terraced, and boulder gardens - 3 km in length and nearly 1 km in width, flanking its famous rock citadel. Ponds, pavilions, fountains and cut pools made up the water gardens. More naturalistic gardens were created around massive boulders, mimicking an artless park with long, winding pathways to saunter down. Brick staircases and limestone steps led up to more formal terraced gardens.

Across it all stretched double moats and triple ramparts, defendable gateways, and steps in perfect geometric symmetry, locking all the elements of the fortress city together with mathematical precision and elegance and pierced by the massive sentinel sculpture of a crouching lion. The beast guards the staircase to the ancient palace six hundred feet above, though all that remains now are the two animal paws, rediscovered in excavations in 1898. Built with bricks and limestone, the lion’s full height was 45 feet.

The whole site was fuelled by a remarkable hydraulic irrigation system - the child of the most advanced water technology in the then-known world Rock-cut horizontal and vertical drains, underground terracotta pipes, tanks, ponds, interconnected conduits, cisterns, moats, and waterways channelled surface water to stop erosion and tapped other water sources to deliver water to the huge ornamental gardens, the city and palace - and harness it to help cool the microclimate of the royal residences.

The consequences of the state’s remarkable achievements in water technology had given rise to similar attainments in many, many other quarters – all of which came to bear down w...