My astute uncle had somehow acquired a house in the Brucheion region, once the royal quarter and still the most magnificent and sought-after place to live. Now that the incestuous royal Ptolemies had been kicked into oblivion by us Romans - deftly cleansing the world of rivals - the district was even more desirable to those with taste. We had glimpsed its atmospheric assets on arriving last night, for Alexandria was home to an enormous lamp-manufacturing industry; the streets here were gloriously lit at night, unlike every other city Helena and I had lived in - Corduba, Londinium, Palmyra, even our own dear Rome, where if lamps were hung up the burglars immediately doused them.

Our ship had berthed very close to my uncle’s house. This good luck was unlikely to last. After more than ten years as an investigating informer, I expected Fortune to allot me kicks, not caresses. But we had even managed to find a trustworthy guide, which suggested the citizens of Alexandria were strangely friendly to foreigners; I doubted it. I was born and bred in a city, the best in the world, and I knew all cities shared the same attitude: the only thing to admire about foreigners is the innocent way they part from their travel money. Still, with the guide’s help, we had found the house so fast, all we saw was that Alexandria was expensive, expansive and extremely Greek in style.

Helena always devised lecture notes. So I knew Alexander the Great had come here towards the end of his conquering adventures, found a clutch of fishermen’s huts decaying beside a deep freshwater lake, and spotted the potential. He was going to build a mighty port to

dominate the eastern end of the Mediterranean, where safe harbours were few and far between. You don’t spend years beating up the world’s famous cities without acquiring a sense of what will impress visitors - and what will last. Alexander had incentives. If you are founding a new place and putting your own nametag on it, you get it right.