Tod of the Fens, by Elinor Whitney

I've had so many books piling up on me these days that Tod took me much longer to finish than it should have! Suffice it to say that it's a load of fun. It takes place in the town of Boston (England) in the 1400s. Tod and his band of men, known only by aliases to each other, live among the surrounding forests. When they get together, their amusement is had in one-upping the others by telling stories of the mischief they have created. But Tod meets a new man, whom he dubs Dismas, who runs the best prank of all! Unfortunately, his true identity prevents him from appearing in person to tell the story.

Dismas' prank sets off a series of events that cause a great deal of distress to Boston's residents, including Sir Frederick (recently beginning a new venture to export wool) and his daughter, Johanna.

I'm not giving away the plot, not because I'm lazy, but because the pranks are too funny to spoil. Unfortunately, this book is pretty rare and you may have trouble getting your hands on it.