AS AN HERB, LAVENDER HAS BEEN IN DOCUMENTED USE FOR OVER 2,500 YEARS.
Romans used lavender oils for bathing, cooking, and scenting the air, and they most likely gave it the Latin root from which we derive the modern name (either lavare--to wash, or livendula--livid or bluish). The flower's soothing "tonic" qualities, the insect-repellent effects of the strong scent, and the use of the dried plant in smoking mixtures also added to the value of the herb in ancient times.
(sources: Lavender by Elen Spector Platt and Lavender: Practical Inspirations by Tess Evelegh; Published in oilsandplants.com/gattefosse.htm)