In 1832, after the death of his uncle, the former chief of police AH Benkendorf, who had no children, Konstantin inherited from the title of count. March 26, 1839 was made adjutant, but having stayed a short time in St. Petersburg, he returned to the Caucasus. In 1844, promoted to colonel.
In 1845, commanding the 1st Battalion of the Kura Jaeger Regiment, formed part of the vanguard of General Passek, Benkendorf participated in Dargin expedition and for the difference in the capture Anchimeerskoy position was awarded the Order of St. George 4-th degree; during the assault Gherzel-village was seriously injured during the evacuation of the main detachment shall be cut back severely Circassians. Losing health of his wounds, he was forced to leave the military service and then held positions in the military-diplomatic part with our armies during the campaigns of Hungary in 1849 and the East 1853-1855. For some time (from 1847 to 1849). He was our military agent in Berlin, August 7, 1849 promoted to major general with leaving in the suite. April 17, 1855 Benkendorf was granted the rank of adjutant-general, and from 1856 until his death in early 1858, he was Envoy Extraordinary at the Wurttemberg court. According to the "Military Encyclopedia" Sytina KK Benkendorf died in 1857, but this is an obvious mistake, many memoirs and "List of persons suites" GA Miloradovich called it in 1858
About his participation in Dargin expedition he wrote in French memories, which in a small number of copies were published in Paris by Prince GG Gagarin in French: