Is it true that the Romanov line died out with Peter III?
Peter III, grandson of Peter the Great, succeeded his aunt, Empress Elizabeth, in 1762. In 1745, Peter had married Sophie of Anhalt-Zerbst who took the name Catherine upon her conversion to Russian Orthodoxy. The marriage was unsuccessful mostly due to Peters impotence and emotional immaturity. Catherine had affairs with Sergei Saltykov and Stanislaw Poniatowski. In her memoirs, Catherine strongly hinted that her son Paul was the son of Sergei Saltykov although Paul did bear some resemblance to Peter III. After a reign of only six months, Peter III was overthrown by his wife who went on to reign Russia as Catherine the Great. If her son Paul was the son of Sergei Saltykov, then Peter III was the last tsar with Romanov blood.
