Short answers, pulled from the story.
Helena Petrovna Blavatsky was born on the 12th of August 1831 in Yekaterinoslav, a town within the Russian Empire that is now known as Dnipro. Her family belonged to the aristocracy with her mother being the daughter of Princess Yelena Pavlovna Dolgorukaya.
After fleeing her marriage to Nikifor Vladimirovich Blavatsky she embarked on what she described as nine years of global travel including visits to Egypt Greece India and the Americas. No independent records exist to verify these claims while historian Nicholas Goodrick-Clarke noted public knowledge rests entirely upon her own uncorroborated accounts.
Helena Blavatsky established the Theosophical Society in September 1875 alongside Henry Steel Olcott and William Quan Judge at a meeting held in New York City. She served as corresponding secretary though she remained the primary theoretician behind the movement connecting Western esotericism with Eastern traditions like Buddhism.
Worsening health prompted Helena Blavatsky to leave India in March 1885 returning to Europe seeking milder climates. She settled first in Naples then moved to Würzburg Bavaria where Countess Constance Wachtmeister became her constant companion until death.
Helena Blavatsky died on the afternoon of the 8th of May 1891 contracting influenza during Britain's winter epidemic at Annie Besant's house at 19 Avenue Road St John's Wood. Her body was cremated five days later at Woking Crematorium marking what Theosophists now commemorate annually as White Lotus Day.