The Astures joined the Cantabri in a common defense. In spring 25 BC, there were three Roman legions established near the Astura River (modern Esla River), with troops from the Tarraconensis. According to contemporary Roman historian Florus in his Epitome of Roman History, the armies of the Astures Transmontani came down from their snow-covered mountains (which is perfectly possible in the Picos de Europa in spring) and settled near the Astura River, getting ready to take the three Roman winter camps.