"Captain Sir Richard Francis Burton: A Biography" by by Edward Rice.

Book Description (Amazon.com Review):

A New York Times best-seller when it was first published, Rice's biography is the gripping story of a fierce, magnetic, and brilliant man whose real-life accomplishments are the stuff of legend. Rice retraces Burton's steps as the first European adventurer to search for the source of the Nile; to enter, disguised, the forbidden cities of Mecca and Medina; and to travel through remote stretches of India, the Near East, and Africa. From his spying exploits to his startling literary accomplishments (the discovery and translation of the Kama Sutra and his seventeen-volume translation of Arabian Nights), Burton was an engrossing, larger-than-life Victorian figure, and Rice's splendid biography lays open a portrayal as dramatic, complicated, and compelling as the man himself.