What is the author's style in Royal Flash, from the Flashman Papers by George MacDonald Fraser?

Royal Flash takes place in the mid 19th century and language is used in such a way as to reflect the time period. As the book takes place in England for the most part, the Queen's English is the language of preference. Although Flash professes to be bilingual, there is little to no French present. When Flash travels to Germany and Strackenz, German and Danish are used, but sparingly. It is fortunate that the reader is not expected to adopt new languages as easily as the main character.