The Riddle of the Sands (1903), a record of secret service recently achieved

According to Wikipedia: "The Riddle of the Sands: A Record of Secret Service is a 1903 novel by Erskine Childers. It is an early example of the espionage novel, with a strong underlying theme of militarism. It has been made into a film and TV film. It is a novel that "owes a lot to the wonderful adventure novels of writers like Rider Haggard, that were a staple of Victorian Britain"; perhaps more significantly, it was a spy novel that "established a formula that included a mass of verifiable detail, which gave authenticity to the story – the same ploy that would be used so well by John Buchan, Ian Fleming, John le Carré and many others." Ken Follett called it "the first modern thriller." The Observer, in a "fundamentally English" list published to coincide with the Big Read campaign in 2003[3], listed the book as #37 on its list of "The 100 Greatest Novels" from the past 300 years... Robert Erskine Childers DSC (25 June 1870 – 24 November 1922), universally known as Erskine Childers, was the author of the influential novel Riddle of the Sands and an Irish nationalist, who was executed by the authorities of the nascent Irish Free State during the Irish Civil War. He was the son of British Orientalist scholar Robert Caesar Childers; the cousin of Hugh Childers and Robert Barton; and the father of the fourth President of Ireland, Erskine Hamilton Childers."