What is the author's style in Sharpe's Tiger by Bernard Cornwell?

The author uses uncomplicated syntax in narratives that are peppered with unusual words and period terminology. When he gives a voice to Sergeant Hakeswill, the style is British street and military slang of the time. Sharpe also uses slang, but not as pronounced. The French Colonel Gudin occasionally uses his native French, while the other characters speak mostly straight English without pronounced accents or very many period expressions. By exaggerating Hakeswill's speech, the character gains color while enhancing the irritation factor that McCandless finds intolerable.