On February 19, 1844, Timashev was sent to the Separate Caucasian Corps, where he arrived in April. On September 17–18 of the same year, he took part in his first battle with the highlanders, for which he was awarded the Order of Saint Anne of the 3rd Degree With a Bow. Having received the rank of adjutant wing on December 6, 1844, in January 1845, he returned to Saint Petersburg. On April 21, 1845, he was promoted to staff captain, and on July 1, 1848, to captain.