Henty "was the most popular Boy's author of his day." Blackie, who published his children's fiction in the UK, and W. G. Blackie estimated in February 1952 that they were producing about 150,000 Henty books a year at the height of his popularity, and stated that their records showed they had produced over three and a half million Henty books. He further estimated that considering the US and other overseas authorised and pirated editions, a total of 25 million was not impossible. Arnold notes this estimate and that there have been further editions since that estimate was made.