The last of the gunslingers and the sole surviving member of a knightly order sworn to protect the Beams that hold the multiverse together. Roland has pursued the Man in Black across a dying world for years, driven by a singular obsession with the Dark Tower - the nexus of all realities. Trained from boyhood in Gilead, he is one of the finest warriors alive, possessed of an almost supernatural speed and accuracy with his revolvers. He is also ruthless, willing to put the quest above all else - a quality that defines him across eight books.

A heroin addict from 1987 New York, drawn into Mid-World through one of the doors on the beach. Quick-witted and irreverent, Eddie has a gift for defusing tension through humour that masks a deep well of courage. He becomes one of Roland's most capable and loyal companions.

A former Catholic priest first introduced in King's Salem's Lot, who crosses into the Dark Tower universe and eventually settles in Calla Bryn Sturgis. Whatever happened to Callahan in his New England parish - and the answer is not the kind of thing a man can give a short version of - left him spending years wandering before finding purpose again with Roland's ka-tet. His backstory occupies a substantial section of Wolves of the Calla.

A boy from New York who finds himself drawn into Mid-World, where he becomes a companion to Roland and his ka-tet. Perceptive and brave beyond his years, Jake possesses a low-level psychic ability and bonds deeply with the billy-bumbler Oy.

An elderly Maine caretaker and local who helps Roland and Eddie escape the ambush at Chip McAvoy's store. A shrewd, laconic Yankee with a collection of signed baseballs, he provides shelter, medical supplies, and crucial local knowledge, including the location of Calvin Tower and information about walk-ins on Turtleback Lane.

A fourth personality inhabiting Susannah's body, whose name means 'mother' in the High Speech. Mia exists solely to protect and nourish what she calls her chap - the strange and uncanny pregnancy Susannah is unwillingly carrying - and the dissonance between her perception of her surroundings (a grand castle, lavish meals) and what Susannah experiences in her body is one of the more disturbing notes of the later books. Whether Mia's interests can coexist with Susannah's is the central tension of the arc she dominates.

A billy-bumbler - a raccoon-like creature native to Mid-World with limited speech ability - who attaches himself to Jake Chambers and becomes inseparable from him. Oy is capable of mimicking words, shows unusual loyalty and intelligence, and serves as both comic relief and emotional anchor for the ka-tet.

A smooth-talking agent of the Crimson King who operates through the Sombra Corporation - one of the more polished faces the Tower's enemies present to the New York end of the Dark Tower story. Sayre's role unfolds across several of the late books, and the further into his orbit the ka-tet's allies on the New York side are drawn, the less the surface civility tends to mean.

The author himself, appearing as a character in his own story - a young, struggling writer living in Bridgton, Maine in 1977 who, several years earlier, began writing about a gunslinger and a dark tower and then, for reasons he does not entirely understand, stopped. The conceit that the writer of the Dark Tower might be a participant in it as well as its author is one of the bolder moves of the later books, and what Roland and Eddie find when they visit Bridgton is one of the things that turn the structure of the series inside out.

A civil rights activist from 1964 New York with dissociative identity disorder, drawn into Mid-World through one of the doors on the beach. Her two identities - the composed Odetta Holmes and the volatile, dangerous Detta Walker - must find a way to coexist. A wheelchair user who lost her legs below the knee in a subway accident, she becomes one of Roland's most formidable companions.

The fat, mild-mannered owner of The Manhattan Restaurant of the Mind, a second-hand bookstore in midtown New York whose proprietor is conspicuously more interested in talking about his stock than in selling any of it. Tower has a curious reluctance to part with one particular piece of family property - a vacant lot at Second Avenue and 46th Street, almost worthless by any sensible commercial measure, that the Sombra Corporation has nonetheless been pressing him with disconcerting persistence to sell.

Enrico Balazar's chief enforcer, known as Cully. A flat-eyed, dangerous man who pursues Eddie through the door between worlds.