The history of the kilt stretches back to at least the end of the 16th century. The kilt first appeared as the belted plaid or great kilt, a full-length garment whose upper half could be worn as a cloak draped over the shoulder, or brought up over the head as a hood.
The small kilt or walking kilt (similar to the ‘modern’ kilt) did not develop until the late 17th or early 18th century and is essentially the bottom half of the great kilt.
The word kilt comes from the Scots word kilt meaning to tuck up the clothes around the body, although the 11th edition of the Encyclopædia Britannica (vol. 15, p. 798) says the word is Scandinavian in origin. The Scots word derives from the Old Norse (meaning lap, the fold of a gathered skirt).
The belted plaid or great plaid, also known as the great kilt, is likely to have evolved over the course of the 16th century from the earlier “brat”
This earlier cloak may have been plain in color or in various check or tartan designs, this earlier fashion of clothing had not changed significantly from that worn by Celtic warriors in Roman times.
Over the course of the 16th century, with the increasing availability of wool, the cloak had grown to such a size that it began to be gathered up and belted. This garment was gathered up into pleats and secured by a wide belt.
The purpose of kilt plaids with belt loops was in use by the 18th century. A surviving men’s belted plaid from 1822 has a belt loop sewn inside it at each pattern repeat, such that it can be unpleated entirely into a blanket.
The upper half could be worn as a cloak draped over the left shoulder, hung down over the belt and gathered up at the front, or brought up over the shoulders or head for protection against the weather. It was worn over a léine (a full-sleeved tunic stopping below the waist) and could also serve as a camping blanket.
Now you all know the history of the kilt.