The Hundred Days is the nineteenth historical novel in the Aubrey-Maturin series by British author Patrick O'Brian, first published in 1998. The story is set during the Napoleonic Wars, specifically in their last portion in 1815, the Hundred Days.

Napoleon escaped his exile at Elba and gained a huge army as he marched up from the south coast of France to Paris, unseating Louis XVIII. The allies of 1813 and 1814 are coming together again to join their armies on land to stop Napoleon keeping the France he has retaken. Forces on the north coast of Africa are raising money to block the allied armies from joining, favouring Napoleon. Aubrey and his convoy are given the mission to destroy shipyards supporting Napoleon along the Adriatic Coast and to stop that money, if it indeed has been raised, from reaching its destination. Maturin and Dr Amos Jacob negotiate in Algiers, where, among other accomplishments, Maturin shoots a lioness leaping at him and the Dey of Algiers.

Reviewers enjoyed this novel, especially that it has all they expect of a novel in this series, plus more of a plot, and one goes so far as to say "This is strictly an adventure tale." Many authors write fictional tales set in the dramatic Hundred Days after Napoleon escaped his exile and induced a conclusive end to the long wars, but "O'Brian has added a clever fictional twist" with the plot bringing the reader to North Africa on a hunt for a galley full of small gold ingots to release a large army of mercenaries to increase the odds of Napoleon's large and rapidly re-built army winning. There is another aspect to the novel, as it starts with deaths, leaving Maturin a widower, so that "its recurring leitmotif is one of the subtlest sketchings of deep, deep grief in literature." What makes this novel special is the "rendering of the internal lives of the characters – his loving and apt portrayal of their rich mix of feelings and experiences". Others note that over the long years of writing this series, the powers of the author have not diminished, yet the characters are "realistically aging" and "their victory is not without cost." The novel's "prose moves between the maritime sublime and the Austenish bon mot, "a man generally disliked is hardly apt to lavish good food and wine on those who despise him, and Ward's dinners were execrable"." Again, the author's staying power as a writer is commended: "O'Brian continues to unroll a splendid Turkish rug of a saga" A key to the success of the novel is O'Brian's "invention of dual heroes, the bluff and ultracompetent Aubrey being always accompanied by his eccentric ship's surgeon, Stephen Maturin", and although the Napoleonic Wars have come to a close, this time for good, the ending of the novel suggests it is not the last adventure for Aubrey and Maturin.

Plot summary

Maturin rejoins the squadron at Funchal after burying his wife, killed when her carriage overturned. Fitted out, Commodore Aubrey's squadron meets at Gibraltar with Admiral Lord Keith, who updates him on Napoleon's success at Paris and the armies gathered on land. He orders Aubrey first to defend a convoy of merchant ships from Moorish xebecs and galleys, and then to proceed to the Adriatic Sea to destroy any new ships being built to support Napoleon. The grieving Maturin, in a separate meeting, learns of a plot to send sufficient gold through Algiers to fund Muslim mercenaries who would block the Russian forces from joining those of the other allies, so Napoleon's army can attack one army at a time. Aubrey's squadron is successful in defending the convoy. The captain of the Pomone is haunted by the faces of the galley slaves who died when his ship attacked theirs; Aubrey reports he died cleaning his guns, and a new captain is assigned to Pomone. The convoy proceeds toward the Adriatic, stopping in Mahón. At sea, they encounter Captain Christy-Palliere, of the Royalist Caroline and an old acquaintance, who informs Aubrey about the French situation in the Adriatic before parting. Amos Jacob is sent out on Ringle to Kutali and Spalato to gain more information. Surprise sinks a French frigate under the command of an Imperialist at Ragusa Vecchia. Jacob rejoins near Porte di Spalato where they meet another French frigate, whose captain, like so many, does not want to declare for Napoleon but fears he will win. Maturin and Jacob negotiate an agreement for the French frigate to fight a mock battle against both Surprise and Pomone; the Frenchman then accompanies Pomone to Malta. Following up the pressure put on banks not to loan to the small shipyards, they lay out gold to push disgruntled dockworkers to burn new French ships along the coast, which is effective.

Reaching Algiers, Maturin and Jacob meet the Consul, Sir Peter Clifford, and his wife. They meet with the Dey's Vizier at Kasbah, the Dey's palace. They travel to meet the Dey, Omar Pasha, at his hunting-lodge at Shatt el Khadna in the Atlas Mountains. The Dey invites Maturin to hunt lions with him. The Dey kills a large lion while Maturin kills its lioness as it leaps to them, saving the Dey's life. For this deed, Omar Pasha swears that no gold will sail from Algiers, and gives Maturin one of his rifles as a parting gift. Jacob befriends Ahmed Ben Habdal, who reveals that Pasha sent a contrary message to the Sheikh of Azgar, to have the gold carried by a fast-sailing xebec from Arzila, near Tangiers, captained by an Algerian corsair via the Strait of Gibraltar straight to Durazzo. Maturin and Jacob return to Algiers, and wait for Ringle to appear. Maturin buys two Irish children in the slave market. Once he sees the Ringle windbound off shore, they engage a local vessel to put them aboard Ringle. Before leaving, they learn Pasha is killed, and replaced by Ali Bey.

Reade relates the damage sustained by Surprise during the fierce storm. They join Aubrey in Port Mahon, and speak with Admiral Fanshawe. Aubrey agrees to pursue the xebec. They encounter Hamadryad under old friend Heneage Dundas, who tells them that Lord Barmouth is in place of Lord Keith. In Gibraltar, Maturin tells Aubrey not to worry about Barmouth, because Peter Arden, Barmouth's political man, respects Lord Keith. Barmouth tells Aubrey to take his broad pennant down, as his squadron is dispersed. Later, Barmouth is joined by his new wife, who he learns is a cousin to Aubrey. On his return, Aubrey finds Barmouth friendly to him, as Barmouth wanted his wife with him. Before leaving for this battle, Maturin leaves the twin children with Lady Keith.

Dr Jacob learns the corsair has two galleys to act as decoys whilst he lies under Tarifa before running through the Strait. The Surprise, Ringle and the blue cutter lie in wait in the Strait. The galley sees three armed ships, and Murad Reis, her captain, fires on the frigate, destroying one gun, and killing Bonden, the coxswain, as well as Hallam, a midshipman. After a long pursuit, the galley hides at Cranc (Crab) island, where Surprise and Ringle, unable to follow the galley into the shallow lagoon, block the exit. A gun from the Surprise is hoisted up a cliff, where it can fire unopposed on the galley. The galley's crew, seeing the situation is hopeless, behead Murad and surrender. Returning victorious to Gibraltar, the Surprise sees the town exploding fireworks, and learns that Napoleon has lost in the Low Countries, fully beaten. Ali Bey sends word he wants the gold; he is killed and the new Dey, Hassan, admits the xebec fired first, and asks for a loan to consolidate his position in Algiers. The xebec is cleaned up and sent to Algiers, while the gold is shared out in Gibraltar. Barmouth worries that his new wife is too friendly with Aubrey, so he sends him off to the venture in Chile.

Characters

Jack Aubrey: Commodore with his pennant on HMS Pomone, shifted at Gibraltar to HMHV Surprise; Captain of His Majesty's Hired Vessel Surprise when the convoy disperses. Stephen Maturin: Ship's surgeon, physician, friend to Jack and an intelligence officer, recently widowed. Sophia Aubrey: Wife of Jack Aubrey and mother of their three children, Charlotte, Fanny and George. Diana Villiers: Wife of Stephen Maturin and mother of their daughter Brigid. Diana dies in a carriage accident in England after the families return from Madeira. Brigid Maturin: Young daughter of Stephen and Diana. Mrs Clarissa Oakes: Governess to Brigid Maturin. Introduced in Clarissa Oakes / The Truelove. Mrs Williams: Mother of Sophia and aunt to Diana. She also is killed in the carriage accident. Padeen Colman: Irish-speaking servant to Stephen Maturin, now part of his household on land. Lieutenant Edwards and John Arrowsmith: Two retired Lieutenants living in Gibraltar who narrate the arrival of Surprise and discuss recent deaths announced in the Naval Gazette.

Intelligence for Royal Navy actions Admiral Lord Keith: Commander-in-Chief Mediterranean Fleet who called Aubrey back into service at Madeira and gives orders once Aubrey reaches Gibraltar. Introduced in Master and Commander. Queeney, Lady Keith: Wife of Admiral Lord Keith and longtime friend of Aubrey. Introduced in Master and Commander. Campbell: Secretary to Admiral Lord Keith, present at the meeting with Maturin. Sir Joseph Blaine: Chief naval intelligence officer, who sends his information by coded letter to Maturin. Mr William Kent: Whitehall official in Gibraltar to meet with Maturin. Mr Dee: Authority on Eastern matters, particularly finance of Muslim states, who is in Gibraltar to meet with Maturin. Dr Amos Jacob: Assistant surgeon on the Surprise. He assists Maturin in languages of the eastern Mediterranean. He was born an Orthodox Spanish Jew, who speaks English, French, Ladino, Hebrew, Arabic and Turkish and he is a Cainite. He has interest in gems and trained in medicine with Maturin. Colvin: From naval intelligence, he meets Maturin at Mahon to tell him of the agreement with bankers not to make loans to small shipyards along the Adriatic Sea, and that if Maturin is willing to work with the Carbonari, they will finish the task of stopping shipbuilding when the shipyards do not pay their workers for several weeks, by setting fire to the yards. Ibn Hazm: Shi'ite Muslim Sheikh of Azgar, at a crossroads in the desert, who is thought by Dee to have enough gold to pay the soldiers who would block the Russian army from meeting with the allies, thus favouring Napoleon.

Crews and officers aboard ships Barrett Bonden: Aubrey's coxswain. He is killed in the action with the xebec. Preserved Killick: Aubrey's steward who assists Maturin as well. Dr Glover: Surgeon on HMS Pomone. Mr Harding: First Lieutenant on the Surprise, introduced in The Commodore. Mr Somers: Second Lieutenant on the Surprise, asked by Maturin to act as his second after Hobden insulted Maturin. Introduced in The Commodore. Mr Whewell: Third Lieutenant on the Surprise, introduced in The Commodore. John Daniel: Master's Mate on the Surprise with a particular love of and skill with numbers, a good navigator. Hobden: Marine Captain on the Surprise. Mr Woodbine: Master on the Surprise. Mrs Poll Skeeping: Loblolly boy on the Surprise. McLeod: Joined at Gibraltar, had been on HMS Centaur when Commodore Hood set his pennant on her at Diamond Rock, and in his youth was a Saint Kilda cragsman; he agrees to aid in bringing a gun up Cranc Island. Charles de La Tour: Captain of frigate Ardent, an Imperialist (supporter of Napoleon), met at Ragusa Vecchia on the eastern shore of the Adriatic Sea.

New allies Guillaume Christy-Pallière: Captain of the Royalist Caroline and long-time friend to Aubrey and Maturin after he captured them; introduced in Master and Commander. Richard: Secretary on the Caroline. Captain Delalande: Captain of the Cerbère, Royalist, who shoots blanks at Spalato, for a dignified display of force to support his stand with the Royalists.

Met at Mahon Admiral Fanshawe: Port Admiral of Mahon.