Pyotr Fyodorovich Tchaikovsky
Paternal grandfather of the composer (b. 1745 in Nikolayevka, near Poltava; d. 1818), born Pyotr Fyodorovich Chayka (Петр Федорович Чайка); later known as Pyotr Fyodorovich Chaykovsky (Петр Федорович Чайковски).
He was the second child of Fyodor Chayka (ca.1695–1767) and his wife Anna (1717–?). Pyotr studied in a seminary in Kiev, but he later received medical training in Saint Petersburg. From 1770 to 1777 he served as a physician's assistant in the army, later becoming a medical officer in Kungur (Perm Region), before transferring to Vyatka in 1782. Three years later he was included (as a member of the landless gentry) in the register of nobility instituted by Catherine the Great. He resigned from his medical service, and became a member of Vyatka City Council in 1789, governor of Slobodskoy from 1795, later governor of Glazov. Recipient of the Order of Saint Vladimir (4th class). He was the first family member to adopt the name Tchaikovsky.
In 1776 he married Anastasiya Stepanovna Posokhova (b. 1751), and they had eleven children: Vasily (b. 1777); Yevdokiya (b. 1780); Yekaterina (b. 1783); Ivan (b. 1785); Aleksandra (b. 1786); Pyotr (1789–1871); Anna (b. 1790, d. in early childhood); Mariya (b. 1792; d. in early childhood); Vladimir (1793–1850); Ilya (1795–1880), father of the composer; and Olimpiada (1801–1874)