The world's richest cartoonist; the world's most popular cartoonist: which rates first? To Charles Schulz, who has died of cancer aged 77, it was definitely the second. His comic strip creation, Peanuts, a catch-all title for a group of knee-high kids in a world no taller than their heads (one of the secrets of the strip's success was that adults were only apparent in the odd off-panel speech balloon), never changed beyond a certain shakiness of line, after it made its debut in American newspapers on October 2, 1950.

Although only eight mid-western newspapers printed the strip, today over 90m people read Peanuts world-wide. Originally, Schulz was paid $3 for each daily strip he drew; a recent estimate paid him $1m a month. And then there was the merchandising.

Charles Monroe Schulz was born in Minneapolis, Minnesota. His father was a small-time barber. Two days after the boy's birth he nicknamed him Sparky, after Sparkplug, the hapless horse owned by Barney Google, the popular comic strip hero drawn by Billy de Beck. It seems like a twist on an old fairy story, for the baby would be involved with comics for the rest of his life.

On his first day at kindergarten, the teacher gave the class sheets of white paper and big crayons, and told them to draw anything they liked. Young Charlie drew a snow scene, then added a palm tree in the background: an unlikely combination, commented on by the teacher, which made the picture stick in the boy's memory, an early illustration of the humorous way his creativity would grow.

When he was 11, the first comic books began publication in the US. Already a devotee of the coloured comic supplements to his father's newspapers, Sparky (as he was now signing all his sketches), began to buy and study each new issue. As with most other beginners in the comic strip trade, he learned to cartoon by copying other cartoonists, filling his drawing books with careful versions of every character he enjoyed, from Popeye the Sailor to Buck Rogers.

Schulz published his first drawing when he was 14. His pet dog Spike, a mongrel with a touch of hunting hound, had a predilection for eating certain unlikely objects, such as pins and razor blades. He sketched Spike and sent the results to the world-famous Robert Ripley, whose Believe It Or Not panels had world circulation. The picture was signed "Sparky" and Ripley reproduced it. The spotted dog bears a certain resemblance to a beagle called Snoopy, co-star of the Peanuts strip.

Schulz's first publication seemed likely to become his only one. At high school he was asked to contribute caricatures to his senior year book. He drew them eagerly but the editor refused to publish them. Meanwhile his father paid for a course in cartooning by correspondence with the Art Instruction School of Minneapolis. It cost him $170 in subscriptions, but was ultimately worthwhile. Schulz would eventually join the staff, but not until after his war service.

Called into the US Army in February 1943, Schulz would be discharged in the rank of staff sergeant. Although he spent most of his service time in Kentucky guarding trucks, he was sent to France two years later, where he drew his everyday adventures in a pocket sketchbook. Returning home, he joined Art Instruction, correcting the homework sent in by students.

He worked under Frank Wing, a perfectionist who was the first man to spot the potential in the cartoons Schulz sketched in his spare moments. Wing persuaded Schulz to submit them to the local newspaper, the Saint Paul Pioneer Press. Although they may not have been aware of it, since the series was called Li'l Folks, local readers were the first to see Peanuts in print. For a while Schulz was delighted enough just to see his drawings appearing regularly, but when the time came for him to ask for an increase in recompense, the editor promptly dropped the feature.

Schulz, however, continued to make up his income by lettering the pages of strips in a locally published series of Catholic comic books, Timeless Topix. He also submitted cartoons to the national weekly, Saturday Evening Post, which bought 15 of them before cancelling out. All the cartoons pointed to the shape of strips to come: they all featured little kids with big rounded heads, and not a grown-up in sight.

It was 1950 when at last fortune smiled in the shape of the United Feature Syndicate. Schulz had sent them a batch of sample strips. They signed him and sent them out to their worldwide customer list. Eight papers responded; all small circulation, but it was a start. A year later Schulz married Joyce Halverson; they divorced in 1972.

From the very first strip Charlie Brown - the champion chump, the favourite fall-guy, the (if-you-like) typical real-life American hero - was the star, and the first character to be named. Then one by one came Linus van Pelt, the first kid to own a security blanket (Schulz's own term, now in Webster's Dictionary); his sister Lucy, the sneery little brat; Schroeder who plays perfect Beethoven on his toy piano; scruffy Peppermint Patty; grubby Pigpen and, of course, Snoopy, the dog given to daydreaming he is a first world war flying ace, and his friend, the yellow bouncing bird, Woodstock. Together they were Peanuts, the only thing Schulz disliked about his strip. He'd gone on calling it Li'l Folks, but the syndicate changed it.

Schulz's first acknowledgement came from his fellow newspaper cartoonists: they gave him their Reuben Award in 1955, the first of many honours including, in 1978, being voted by his peers across the world of cartoonists as international cartoonist of the year. Peanuts made the cover of Time Magazine in 1965. The first Peanuts book was published in 1952 (20 years later there were 190 of them); the first of 16 television cartoons was made in 1965; the play You're A Good Man Charlie Brown opened on Broadway in 1967; and the first feature film cartoon was produced in 1969, the year that Charlie Brown and Snoopy went truly out of this world - as mascots of the Command Capsule and Lunar Module of NASA's Apollo 10.

Schulz spent much of his time at the Redwood Empire Ice Arena in Santa Rosa, where he played hockey or had coffee at the appropriately named Warm Puppy snack bar. Frequently asked the secret of his characters' appeal, Sparky Schulz would reply: "If you read the strip regularly you know everything there is about me." And as he once confided to the Washington Post: "My whole life as been one of rejection. Women. Dogs. Comic strips." As Charlie Brown was wont to remark: "Good grief!"