Tristram begins his autobiography at his conception, complaining that his parents approached his creation without planning or forethought. He believes this was the start of his misfortunes, as his humors were out of balance from the very start. Tristram’s birth was equally disastrous, but before narrating it he feels compelled to explain the context.
Tristram digresses, narrating the history of the local midwife and the parson, Yorick, and explaining his own theory of hobby-horses. Tristram becomes caught up in the story of Yorick’s life and death before returning to his own birth. He then quotes from his parents’ marriage contract, explaining the legal battle between Walter and Elizabeth Shandy over where their child will be born and under what kind of medical supervision—Walter is able to compel his wife to give birth at their country home, Shandy-Hall, rather than London, but while he wants a professional doctor, Mrs. Shandy insists on the midwife instead.
Tristram strays from the subject again, explaining to the reader Walter’s theory that first names determine one’s character. The choice example is Tristram’s great aunt Dinah, whose coachman impregnated her. Walter’s obsession with this story greatly upsets his modest brother Toby. Tristram believes that Toby’s character is best shown through his personal hobby-horse: fortifications.
Toby was wounded in the groin at the siege of Namur and fell into a depression during his yearslong recovery. He became obsessed with fortifications as a means of making sense of his injury and reads all the military science literature he can get his hands on. Toby’s manservant Trim, a fellow disabled veteran, suggested that they move beyond maps and books and model the fortifications themselves on the bowling green at Shandy-Hall.
Tristram returns his focus to the moment of his birth: Walter and Toby are in the parlor while his mother is in labor in her room. They are joined by the bumbling Dr. Slop, whom Walter has called in case the midwife needs help. As the men wait Toby steers the conversation toward engineering and fortifications, much to Walter’s annoyance. Toby has Trim read from a book on the subject by Stevinus, but a sermon by Yorick on conscience falls out of the pages and Trim reads that instead, provoking a religious debate. Returning to the impending birth, Tristram explains that his father wants Dr. Slop to oversee it because of another theory of his: that head-first births damage the brain.
Dr. Slop is unable to open his bag of medical equipment, which Walter’s servant Obadiah has tied shut with extremely tight knots (Dr. Slop had forgotten the bag at home earlier). Walter then reads in full an excommunication written by Ernulphus, which he believes is the pinnacle of the art of cursing. The maid Susannah then informs them that the midwife has fallen, and Dr. Slop will have to perform the birth after all. Walter and Toby stay in the parlor and Walter philosophizes about time and duration, which mostly goes over Toby’s head. They fall asleep, and Tristram uses the opportunity to add in a preface to his book, musing on the human qualities of wit and judgment.
When Walter and Toby wake up, they learn that Dr. Slop is building a bridge, which Toby assumes is for his model fortifications—in fact it is for Tristram, whose nose has been crushed during birth. Walter, who is very proud of the Shandy family’s long noses, is mortified and collapses in bed. Tristram explains Walter’s extensive research on noses and promises to translate a story by the great nose scholar Slawkenbergius with the reader.
In Slawkenbergius’s story, a stranger with an enormous nose arrives in Strasbourg, throwing the whole city into disarray. The stranger, looking for his lover Julia, is oblivious to this, but the citizens of Strasbourg are so obsessed with his nose that the French army is able to seize control of their city.
Tristram returns his focus to his father, who is still in despair on the bed. After Toby consoles him, Walter resolves to counteract the loss of Tristram’s nose by giving him a distinguished name: Trismegistus. Susannah, however, misspeaks to Yorick’s curate and the child is christened Tristram, Walter’s very least favorite name.
Walter, Toby, Trim, and Obadiah accompany Yorick to dinner with several other priests to discuss the possibility of re-christening Tristram. Yorick’s case is undermined, however, by an unfortunate coincidence: a hot chestnut falls into Phutatorius’s breeches, and Phutatorius assumes it is one of Yorick’s pranks. Back at Shandy-Hall Walter’s mood improves when he learns that Dinah has died and left him 1,000 pounds; he considers whether he should spend it on sending Tristram’s older brother Bobby to Europe or enclosing a nearby field. Walter’s indecision is abruptly ended by more bad news: Bobby has died.
Tristram goes on a tangent about whiskers and stresses the malleable nature of language. Returning to Bobby’s death, Tristram recounts Walter’s impassioned speech on grief. Walter’s free-wheeling oration style greatly confuses both Toby and Mrs. Shandy, however. At the same time Trim gives an equally passionate speech about death to the servants in the kitchen. Walter, now resolved to enclose the field and focus on raising Tristram, starts writing a book to educate his son called the Tristrapoedia. Tristram grows older much faster than his father can write, however, making the Tristrapoedia redundant.
Meanwhile, new misfortunes occur: Susannah accidentally lets the window fall onto Tristram’s penis, circumcising him. The incident doesn’t bother Walter, who cites many positive historical examples of circumcision. Walter, Yorick, Dr. Slop, Toby, and Trim read from the Tristrapoedia and discusses Walter’s theories of education and medicine.
Walter wants to procure the very best of governors for Tristram. Toby suggests Le Fever’s son, and Tristram promises to tell the reader the story of Le Fever. Shortly after Toby and Trim moved to Shandy-Hall to build fortifications, they learned that a fellow veteran, Le Fever, was dying of disease in the local inn. Toby promises to care for Le Fever’s son, sending him to school and giving him money to go fight the Turks. Le Fever’s son is now returning to England after several years of unsuccessful war, and Toby believes he would be the perfect governor for Tristram.
Tristram then describes Toby and Trim’s model sieges, which perfectly mimic the actual war in Flanders; Trim is even able to make their model cannons fire by rigging them to his Turkish tobacco pipes. The sieges suddenly come to an end, however, with the signing of a peace treaty in Utrecht, much to Toby’s dismay. This forced end to Toby’s hobby-horse does however set the scene for Toby’s amours with widow Wadman, which Tristram promises to narrate soon.
Death suddenly comes for Tristram on account of Tristram’s poor health, interrupting Tristram’s work on his autobiography and forcing Tristram to flee to the south of France. Tristram describes the country in a mock-travelogue as he runs from Death. Adventures and misadventures abound, and Tristram both praises and criticizes the French way of life. At long last, Tristram manages to escape death. He settles in Avignon, where he promises to sit down and tell the story of Toby’s amours at once and to narrate it in a clear, straight line.
Tristram muses on the fickle nature of both love and women, contemplating what attracts widow Wadman to Toby so strongly. He explains that when Toby and Trim first moved to Shandy-Hall it was still unfurnished and Toby had to stay with widow Wadman. She soon fell in love with him, but he was too obsessed with his sieges to reciprocate until the treaty of Utrecht. Widow Wadman’s garden is next to the bowling green, and she often observed Toby’s sieges and asked him to explain them as an opportunity to flirt.
After the treaty of Utrecht, Toby and Trim demolish the fortifications. To cheer his master up, Trim tries to tell him the story of the king of Bohemia and his seven castles, but Toby’s constant interruptions prevent him from finishing it. Trim then tells Toby the story of when he fell in love with a Beguine nun after being wounded in Flanders. Widow Wadman seizes the opportunity to seduce Toby while love is on his mind. Toby resolves to declare his love to her chivalrously, and Trim plans to seduce her maid Bridget to help his master. Walter, Mrs. Shandy, Yorick, and Dr. Slop all congratulate Toby.
Later, Toby and Trim declare their respective loves to widow Wadman and Bridget. Widow Wadman, however, is concerned that Toby’s wound has left him impotent. He misunderstands her questions and sends Trim for a map of Namur to show her exactly where (geographically) he was wounded. Bridget confesses her mistress’s worry to Trim, who eventually feels compelled to tell the blissfully ignorant Toby the truth. Modest Toby is aghast, and they go over to Walter’s to discuss the matter. Everyone else has already heard, however, as both widow Wadman and Bridget have confessed to Mrs. Shandy and Susannah, respectively, and the news of Toby’s possible impotence has traveled.
Walter seizes the opportunity to demonstrate the immorality of women, but then Obadiah interrupts him, explaining that the cow that Walter’s bull has inseminated is still refusing to give birth. Walter vigorously defends his bull against criticism, comparing it to an honorable man being dragged through the mud in divorce court. Mrs. Shandy is extremely confused. She curses her husband, asking what the story he is telling is even about. Yorick responds gleefully that the story is about a cock and a bull and is one of the very best he has ever heard.
