Short answers, pulled from the story.
Elizabeth of Russia reigned as Empress from 1741 until her death on the 5th of January 1762. She seized the throne on the night of the 25th of November 1741 with the support of the Preobrazhensky Life Guards Regiment, deposing the regent Anna Leopoldovna and the infant Emperor Ivan VI.
Elizabeth vowed before taking power that she would not sign a single death sentence, and she upheld that vow throughout her reign. However, her rule was not without cruelty: political opponents had their tongues removed and were publicly flogged, and she ordered that the imprisoned Ivan VI be killed if he attempted to escape.
Alexei Razumovsky was a Ukrainian Cossack serf who was brought to Saint Petersburg to sing in a church choir. Elizabeth purchased him from a nobleman for her own choir, and he became her long-term companion. In 1742 the Holy Roman Emperor made him a count, and in 1756 Elizabeth made him a prince and field marshal. There is reason to believe they may have married in a secret ceremony, though this was never confirmed.
Elizabeth commissioned numerous major construction projects, primarily through her favourite architect Bartolomeo Rastrelli. These included the reconstruction of Peterhof Palace between 1745 and 1755, the Smolny Convent, and the Winter Palace in Saint Petersburg. The Winter Palace is said to contain 1,500 rooms, 1,786 doors, and 1,945 windows; Elizabeth died before its completion.
Elizabeth allied Russia with France and Austria against Prussia and directed a sustained military campaign that brought Frederick the Great close to surrender. Russian forces crushed the Prussians at Kunersdorf on the 12th of August 1759 and briefly occupied Berlin in 1760. Her death on the 5th of January 1762 ended Russian involvement before Prussia's defeat was secured, an event Frederick the Great called the Miracle of the House of Brandenburg.
Elizabeth's father was Peter the Great, Tsar of Russia. Her mother was Catherine, later Catherine I of Russia, who began life as a washerwoman and housemaid and was the daughter of a Lithuanian farmer named Samuel Skowronski. Peter and Catherine married officially on the 9th of February 1712, after Elizabeth had already been born.