David Scarpa’s screenplay covers three decades of European history as the military commander triumphs in the Revolutionary Wars and rises to Emperor of France, only to end his life in exile.

Numerous times in Napoleon, the mist settles over wintry landscapes, delicately summoning visual echoes of The Duellists, the 1977 debut feature set during the same period that put Ridley Scott on the map. Then there are muscular, large-scale scenes of warfare more characteristic of the veteran director’s later work, notably the Battle of Austerlitz, where cannon fire from Bonaparte’s army sends Austrian and Russian troops plunging to icy deaths in a frozen lake, its water stained with blood. But for all its brawn and atmosphere and robustly choreographed combat, this is a distended historical tapestry too sprawling to remain compelling, particularly when its focus veers away from the central couple.

Abel Gance’s 1927 French silent film, also titled Napoleon, is the most famous screen portrayal of the historical figure. It spent five-and-a-half hours following the protagonist from his formative childhood years through the early upheavals of the Revolutionary Wars and ending in Italy, with visions of future battlefield glory filling the 26-year-old military leader’s head.

David Scarpa’s screenplay opens in 1793 with the guillotining of Marie Antoinette and the unrest in France that creates an opportunity for Napoleon to make a name for himself as a gifted military strategist. He achieves this at the Siege of Toulon, where he leads troops to take the Anglo-Saxon fleet by surprise, securing the harbor and thus reclaiming the town for the Republic.

The film proceeds through a timeline that will be familiar to history students, if probably not altogether lucid to anyone hoping to get a crash course here — the downfall of Robespierre; the end of the Reign of Terror; the conquest of Egypt; the 1799 coup that overthrew the existing French system of government; Napoleon crowning himself Emperor of France in 1804; the decisive Battle of Austerlitz; the failed attempts to establish peace with England and forge alliances with Prussia and Austria; the French invasion of Russia with its heavy losses; Napoleon’s abdication and initial banishment to the Mediterranean island of Elba; his return to lead France in a humiliating defeat against England; and his ultimate exile to the British-controlled island of St. Helena in the South Atlantic.

That’s a lot for any audience to digest in a single sitting, and while Scott can be commended for his ambition, neither he nor Scarpa manage to build those many plot pieces into a fluid narrative.

That unusual dynamic between one of the most powerful men in the world and a spouse who not so long ago was in prison might have been enough to give Napoleon a more consistent pulse had their scenes together been given space to breathe and develop. But Scott is always too eager to get back out in the field, where Napoleon’s letters home to Josephine have to maintain the thread.

Despite frequent bouts of sex amusingly played by Phoenix like a rutting farm animal, Josephine’s belly remains empty. But she blithely deflects the blame onto her husband at the dinner table, calling him fat. In one of many touches of gonzo humor that animate Phoenix’s performance, he snaps back: “Destiny has brought me here! Destiny has brought me this lamb chop!” The unwillingness to acknowledge defeat of any kind, be it marital or military, is a key trait of the characterization, making it both funny and pathetic when Napoleon shouts “We are winning!” on a battlefield strewn with the corpses of his infantry.

But somehow, none of this adds up to a well-rounded portrait of one of the most driven men in history; at times I wondered if Phoenix was still in character from Beau Is Afraid. Kirby’s sly wit, cat-eyed sensuality and innate regality make Josephine the more intriguing figure and certainly make Napoleon’s addiction to her understandable. But there should be real poignancy in him being manipulated by his mother and other advisors into divorcing her and producing an heir elsewhere, even if he remains devoted to his ex-wife with a love that continues after her death.