Flashman on the March is, sadly, the last historical novel of the late George MacDonald Fraser's "Flashman Papers."
The character Harry Paget Flashman was based on the ruffian who bullied Tom Brown in Tom Brown's Schooldays, by Thomas Hughes (1857). Fortunately for Tom Brown, "Flashy's" reign of terror at Rugby School ended when he was expelled for drunkenness. In 1839 Flashman joined the British Army and ended up--against his will--in just about every conceivable conflict of the 19th Century.
Nearly everyone in Victorian Society believed Flashman to be a paragon of virtue and military prowess. But the reader knows better. Because Flashman is, by his own admission, a scoundrel of the first order.
There are 12 Flashman books in the "Flashman Papers" and each one of them are some of the best historical novels ever written. They're presented as memoir packets supposedly written by Sir Harry Flashman himself between 1900 and 1915, with Fraser claiming to be the "editor."
Wikipedia does a credible job of compiling everything there is to know about the life & times of Sir Harry:
Normally I don't read books featuring anti-heroes as protagonists. However, these "memoirs" are written with a trace element of regret and are just plain, laugh-out-loud funny!
Despite the comedic slant, all the novels are meticulously researched. Each book is chock-full of footnotes and end notes. While this often disrupts the narrative of the story, the obscure facts Fraser managed to unearth make fascinating reading in and of themselves.
Here's a short bio of Flashman's creator: