thumb|Coat of arms of the of 1692, in the [[Baltic Coat of arms book by Carl Arvid von Klingspor in 1882.]]
Ludwig Karl August von Hagemeister (; ) was a Russian naval officer who held the rank of captain 1st rank in the Imperial Russian Navy. He was a maritime explorer of Alaska and the Pacific Ocean, and served briefly in 1817–1818 as the second chief manager of the Russian-American Company.
Naval career
Hagemeister was born to an ethnic Baltic German family in the Russian Empire. He began his service in the Russian naval forces in 1795 as a volunteer midshipman. Along with a group of fellow junior servicemen, he joined the British Royal Navy in 1802 on board .
In 1806 he was directed to take with provisions needed to Russian America; this was the first of three circumnavigations in his career to New Archangel. Commanding the Kutuzov, Hagemeister started his second circumnavigation in 1816. Hagemeister arrived at New Archangel during 1817, with his second-in-command, Semyon Yanovsky.
Before examining Baranov's financial records, Hagemeister traveled to northern California to formalize relations with the Kashia Pomo people. He was the principal negotiator with leaders of the local Pomo band, and obtained the privilege to establish Fort Ross. The parties signed a treaty on 22 September 1817, with tribal officials reported to have said that "They are very pleased to see Russians occupy this land, for they now live in safety from other Indians who used to attack them from time to time. This security began only from the time of Russian settlement." The agreement was made by RAC officials as a part of a scheme to take over Alta California from the Spanish Empire.
Returning to New Archangel, Hagemeister and other naval officers spent the winter examining the financial records of the RAC. Sources disagree on what was found: Khlebnikov says that the records showed no evidence of malfeasance. Borneman says that they found a discrepancy in the amount of supplies listed in accounting records. This policy was contained in the Ukase of 1821, a decree from the Imperial Government that extended Russian land claims to northern California and banned all non-Russian European merchants from the area.
Hagemeister appointed his direct second-in-command, Semyon Ivanovich Yanovsky, as the next Chief Manager.