 The East Roman Empire used auxiliary forces known as "dromedarii", whom the Romans recruited in desert provinces.The camels were used mostly in combat because of their ability to scare off horses at close range (horses are afraid of the camels' scent), a quality famously employed by the Achaemenid Persians when fighting Lydia in the Battle of Thymbra (547 BC).The United States Army established the U.S. Camel Corps, stationed in California, in the late 19th century.