It’s not often that you read such an interesting book that so completely fails in its stated intent. What Katherine Frank is trying to do is write the interlinked biographies of two men, Daniel Defoe and Robert Knox, to show how the real-life adventures of Robert Knox were the key inspiration behind Defoe’s creation of Robinson Crusoe. In that, she fails. But the failure is probably more interesting than her succeeding would have been. Yes, she does show quite clearly that Defoe had read Knox’s book of his 20-year captivity on Ceylon (Sri Lanka as it is now), and indeed that he’d simply lifted, whole and entire, some of Knox’s work into his own (in particular the seldom read sequel to Robinson Crusoe). But Defoe stole from other writers with as much panache and as little guilt as he defrauded tradesmen and bankers. Given the prevalence of nautical yarns of adventure and shipwreck at the time, and Defoe’s evident reading of other works in the genre, there’s nothing to say that Knox was the key influence on Crusoe. In fact, quite the opposite, as what defines Crusoe apart from all the real-world shipwrecked sailors is that he never ‘went native’. Rather, he recreated his lonely isle as a little England, remaking it in his own image. That is something that very much comes from Defoe’s own life, and how he remade his disasters and failures as triumphs. In some ways, Defoe was the first of the positive thinkers.

So if Frank fails in what she intended, where does she succeed? For one, in her vivid portrayal of Robert Knox. At the age of 19, accompanying his father on a voyage to the Indies aboard an East Indiaman, storm damage forced them to land in Trincomalee in Ceylon. At the time, the western coastal areas of Ceylon were controlled by the Dutch, but the Kings of Kandy maintained their independence in the mountainous interior of the island. Coming ashore, Knox, his father and a party of twenty sailors were initially welcomed by representatives of the king, but then taken captive.

It was a strange sort of captivity. The men were split into ones and twos and assigned to villages, for the villagers to look after. They were free to move about within bounds, and given food and accommodation, but they were not free to leave. There was, in the end, no meeting with the king, but just this ongoing captivity. It has the quality of a tropical, multicoloured Kafka (if such a thing can exist). Knox’s father died after a couple of years captivity, but on his deathbed his son promised him that he would endure and escape, to carry word back to England to the rest of the family of what had happened to Knox senior.

After 20 years (20 years!), Knox and another member of the crew did escape, making their way overland to a Dutch fort in the north east of the island and then taking ship back home. During the long voyage home, Knox wrote a detailed account of his time in Ceylon, and the geography and customs of the people of the island. Returning, a stranger, to England, Knox found it so very different from his departure. The Commonwealth was finished; there was a king again, and he needed employment. So, a year later, Knox set off sailing again, this time captain of an East Indiaman. But before he left he gave his manuscript, which had been worked through by his cousin and also the great scientist Robert Hooke who had befriended Knox on his return, and in his absence the book was published and became a best seller.

Frank tells this story wonderfully well, and brings Knox vividly to life. She visited Sri Lanka and tracked down the locations where Knox lived. Indeed, for my part as the son of a Sri Lankan, I would have happily had her write Knox’s biography alone, and to have learned more of what he learned and recorded of the country then. This is where the book is at its best, but because of the shared narrative, we don’t spend as much time in the tropics with Knox as we might.

On the other hand, the time spent with money grubbing Defoe in the streets of London is just as vivid and exciting. It’s a shame Frank didn’t write two books, one on each man, with maybe a nod towards Knox’s influence on Defoe, and a big embrace towards the strange way a writer will take influences and ideas and remake them under the demands of the blank page.

But, nevertheless, Crusoe was a real pleasure to read.