Complex sentence: On 31 October 1721, Peter I was proclaimed Emperor by the Senate-the title used was Latin "Imperator", which is a westernizing form equivalent to the traditional Slavic title "Tsar".
Split into simpler sentences: On 31 October 1721, Peter I was proclaimed Emperor by the Senate. The title used was Latin "Imperator", which is a westernizing form equivalent to the traditional Slavic title "Tsar".