Book excerpt: From the moment man learned how to ascend off the ground, the strategic significance of air intelligence became apparent. This relatively new discipline_the first dedicated air reconnaissance missions were undertaken in 1870 during the siege of Paris when tethered French balloons were employed to spot enemy positions and direct artillery fire onto them_has developed at an astonishing speed. Over the past century air intelligence has moved from hazardous observation balloons to micro-circuitry, which can send pictures from a video camera mounted on a remotely-controlled vehicle the size of a hummingbird. The Historical Dictionary of Air Intelligence relates the evolving history of the rapidly advancing field of air intelligence. A chronology, an introductory essay, and cross-referenced dictionary entries on the agencies, agents, operations, equipment, tradecraft, and jargon of air intelligence make this reference as essential as it is fascinating.