The word “pajamas” comes from India, where it was originally spelled “pyjamas” and meant “leg covering.” It was initially an outdoor garment rather than sleepwear.

The British popularized it in the 19th century, but colonists returning from India were the first to make it widely known.

Before pajamas, most people either wore nightshirts, regular clothes, or nothing at all to bed.

They didn’t become extremely popular until the 20th century. It was once considered scandalous and rebellious for women to wear them—even in the 1920s.

The classic button-up pajama became popular after World War I.

Cartoon-themed pajamas for kids became popular around the 1970s.

Some countries mandate fire-resistant pajamas for children.

Some pajamas today are made from recycled plastic water bottles.

Pajamas were once considered a political statement of Anti-Westernism during the Cultural Revolution in Communist China.

In ancient Egypt, people wore linen wraps as an early form of pajama-like clothing.

Luxury pajama sets today can cost $1,000 or more, with the most expensive often made from vicuña wool sourced from South America.

The onesie pajama gained popularity in the 2010s thanks to advertising and television marketing.

Today, many people have traded classic pajamas for T-shirts and soft lounge pants.