My most popular series is the eight book 'On Hadrian's Secret Service', which features the adventures of a Roman secret agent, Gaius Flaminius Drusus, during the reign of the emperor Hadrian. His missions take him from the moors of Caledonia to the deserts of Egypt and Libya, in a never-ending quest to protect the empire from those who wish it harm.
The first book in the series is available as a free offer in the US from this link: https://ebookdaily.com/free-kindle-ebooks/2021-10-02/B00W45H6YM
More recently I have begun another historical spy series, Gestasveit, set in Viking Age Norway.
Also in a historical vein, I have written two books and a collection of articles about the Wirral Peninsula in northern England. These include my first published work, Wirral Smugglers, Wreckers, and Pirates. I also am frequently asked to deliver presentations on the subject. More of this in the 'Public Speaker' and 'Local Historian' sections.
I also write science fiction and fantasy, including a series of sword and sorcery novels featuring SInbad, beginning with a Sinbad / Cthulhu Mythos mash-up called 'Sinbad and the Great Old Ones' and my 'Man from the Colosseum' series, whose hero, Marcus, is employed by the Roman emperor to hunt down strange and remarkable beasts for the arena. In the first story, 'Crocodile and Leopard', he is sent to Ethiopia, where he discovers a lost plateau inhabited by giant saurians...