Energetic until her death in 1796, she would rise at six a.m., let the greyhounds into the garden, drink the first of five cups of black coffee and start on her letters.“I still love to laugh,” Catherine the Great wrote to a confidante who had grown old with her.That most appealing human quality illuminates “Catherine the Great: Portrait of a Woman,” a new biography of the Russian empress by Robert K. Massie.In 625 pages, Massie describes how Sophia, the young daughter of a noble German nobody, became -- after a religious conversion, name change, marriage and murder -- the remarkable tsarina who deserves a big book.Lots of Annas, Annes, Catherines and Peters, many Orlovs, assorted princes, kings and decrepit dukes animate Massie’s meticulously detailed study of the complex state of European affairs in the last 50 years of the 18th century.For a while, there was also a deranged teen tsar locked up in a fortress, until the poor thing was no more.Hovering in the background was the malicious little Prussian, Frederick, also called “the Great,” though he was less deserving of the honorific.It was the lot of this flute-playing, women-loathing martinet to soldier through life at a time when two queens who hated him occupied important thrones.Frederick’s destructive campaigns against Maria Theresa of Austria and Elizabeth, the Russian empress, nearly bankrupted Prussia, until the tsarina suddenly died and his luck changed.Her successor, Peter III, husband of Catherine, now bumbled into view, a Prussia-adoring dimwit who hailed from the geographically tormented duchy of Holstein-Gottorp, known also as the birthplace of Catherine’s mother, and many pretty cows.I know that was quite a bit of information to absorb. And I’ve yet to mention the Swedish king, also a player, or poor Stanislaus Poniatowski, who took a shortcut from Catherine’s bedroom to Poland’s throne. He was not happy with the promotion and wrote her importuning letters as in “Please, Matushka! Not Poland!”Back to Peter III. A pitiful presence, unlike his uncle, Peter the Great, he spent his nights commanding an army of Prussian toy soldiers on the mammoth bed he shared with Catherine, who might wearily maneuver tiny hussars around the pillows before falling asleep.Their sexless charade continued for nine years, Catherine recalled in her memoir.There’s some evidence Peter suffered from phimosis until a surgical intercession helped him out.Regardless, he comes across as hard to love: disfigured by smallpox, passive-aggressive and prone to sawing away at the violin at odd hours. He smoked, drank and sulked when Catherine beat him at cards, which she learned not to do.Finally, Catherine took a lover, Sergei Saltykov, the first of several. The list is actually fairly short and exclusively human, never mind the scurrilous obsession with her sex life that enemies promoted.She chose shrewdly: Gregory Orlov helped make her empress; Gregory Potemkin enlarged her empire all the way to the Crimea. Massie, by the way, notes there’s no evidence this overachiever tried to fool his smart sovereign by putting up “Potemkin villages” -- mere facades with nothing behind.Peter ruled for just a few months. When it became obvious that he hoped to shove her aside in favor of his mistress, Catherine moved quickly late one night.As the legendary Preobrazhensky Guards cheered, Catherine dressed herself in their uniform and jumped astride a white steed to lead the coup, sword at her side.Peter lasted barely a week once he was cornered and locked up in a stone house in Ropsha. You almost feel sorry for the poor wretch as he whimpered and wrote groveling letters to his soon-to-be widow. A few of the officers strangled him with a scarf, perhaps accidentally, during a drunken dinner. Catherine accepted their apologies.Massie, who has written prize-winning biographies of Peter the Great and the Romanovs, gives an exciting account of the chaotic days that changed the history of Russia. Now in his 80s, he has lost none of his taste for the delicious convolutions of court intrigue.Catherine ordered up a fine large crown and quickly got on with the business of capably ruling a huge empire. Blue-eyed and slimly voluptuous, the empress captivated rough soldiers and brainy philosophers.At a time when Russians were still considered socially retarded, she corresponded in perfect French with the intellectuals of the Enlightenment, especially Voltaire, who thought she was a goddess, and Diderot, the impoverished if celebrated editor of Europe’s first great encyclopedia.Hearing Diderot couldn’t afford a dowry for his daughter, she bought his library. Then she insisted he keep all the books, since he needed them more.In thanks, Diderot undertook the difficult journey to St. Petersburg, losing his wig en route, and amused his patron by banging on her thighs when he wished to make a point.Every day for two hours, editor and empress conversed on topics that included the benefits of commercial competition and the usefulness of anatomy classes for girls (helps thwart seducers).Catherine would affectionately remember the French eccentric for his “brown eyes, heavy and sad, as if recalling un-recallable errors, or realizing the indestructibility of superstition, or noting the high birth rate of simpletons.”Inspired by Enlightenment ideas, Catherine turned to composing her Nakaz, a revision of Russia’s legal code, setting out her rules for enlightened governance.Channeling Locke and Montesquieu and so many of her adoring European pen pals, she argued against excessive punishment, decried slavery and spoke ardently for a free press.Then she fumed for months as she -- shrouded by curtains -- observed her ungrateful regional representatives tear the document to shreds. They did not wish to be quite so enlightened! Even the Europeanized nobles, who were usually her greatest supporters, loved their serfs.The French Revolution also encouraged a course correction. (Massie offers a bizarrely amusing discourse on severed heads still blinking at the world).Unsurprisingly, the empress adopted a more conservative style as she aged, though her disgust with torture remained steadfast and makes for interesting reading in our own time.“All punishments by which the human body might be maimed are barbarous,” she wrote.Before a stroke killed her after 34 years of rule, she described herself in an epitaph: “She forgave easily and hated no one. She was good-natured, easy-going, tolerant, understanding and of a happy disposition. She had a republican spirit and a kind heart.”Massie writes that he wished to present a portrait of the empress as woman. More than that, he has given us a portrait of a remarkable human being.