Though it may be hard to believe, it’s that time of the year again. And, as you’ve probably heard on the radio at least 15 times in the past month, Santa Claus is comin’ to town.

While Santa is a staple of millions of people’s Christmas traditions, how many really know the story behind the jolly, white-bearded fellow?

The earliest signs of the Santa Claus of Christmas present can be traced back to St. Nicholas, the beloved religious figure who traveled Turkey in the third century to help the poor and, as part of his efforts, left children secret gifts to brighten their days.

However, many hallmarks of Santa’s style didn’t appear until much later in the decades that followed the American Revolution — the 1800s, to be exact — and most can be attributed to literary descriptions or early sketches of the mysterious man with the bag.

Washington Irving’s 1809 book “A History of New York” described a St. Nicholas-like character who flew above the city. But it was Clement Clarke Moore’s 1822 poem “A Visit from St. Nicholas” (you may know it as “‘Twas the Night Before Christmas”) that first referenced the sleigh, the bag of toys, and the grand entrance through the chimney.

Later, starting in 1862, artist Thomas Nast contributed holiday drawings of Santa to Harper’s Weekly magazine. The illustrations portrayed a jolly, portly figure in the familiar fur who lived at the North Pole and had a bustling toy workshop. From then on, the image of Santa — and his position as a beacon of Christmas cheer — was firmly entrenched in American culture.

Advertisers and retailers jumped on Santa’s sleigh, and faster than you can say, “Ho, ho, ho,” he was in shopping malls across the country. So this year, when you’re knocking back some eggnog and waiting for Kris Kringle to decide whether you’ve been naughty or nice in 2015, at least you can say, “Now I get it.”