I find it amusing that the English are so proud of their heritage, and yet (in Georgian and Regency England, anyways) so mad for anything foreign. If some new fashion came from France, or Germany, or India, or the Orient, they went for it. (Of course, I’m totally proud of being American and yet melt into a puddle whenever I hear British or Australian accents, so it sorta makes sense.)
The banyan is one such thing. But in this case, they clung to it for practical reasons, as well.
The English banyan is an Indian word which denotes a fitted, double-breasted, long, gown with fitted sleeves and often with sewn in waistcoat fronts and frequently quilted. When at home in casual settings with family or friends, cultivated men in the 18th century exchanged their uncomfortable wigs and tight tailored frockcoats for a loose-fitting, long gown or robe. It was even considered stylish to receive visitors in the morning dressed in a banyan. Many of these garments were lined with wool, velvet, or silk plush—a velvet with long pile resembling fur.
Their casual wear usually included a cap, which looks a lot light a nightcap, only it was usually quilted and then adorned, often with a tassel. I’m sure it aided in keeping warm in chilly temperatures, especially since so many men who wore wigs shaved their heads. Men in casual dress also exchanged boots or pumps for a pair of slippers.
Keep in mind, this was not the same as showing up in their bathrobe. It was still considered being fashionably dressed, just more comfortable. They wore their banyans with a linen shirt and cotton stockings, with knee breeches and often a waistcoat.
Banyans of the early eighteenth century, were fairly full and flowing, more like Japanese Kimonos. But by the Regency, they consumed much less cloth and were more fitted through the upper body. In most cases, silk frogs secured the front closed although some men used gold clasps which had to be removed each time the banyan was laundered, then re-attached. I’m sure valets hated those, since they had to remove and re-attach the gold clasps prior to laundering.
A dressing gown, morning robe, or robe de chamber, were all similar items to the banyan, but since the Indian word banyan sounded so much more exotic, the name stuck. By the late 19th and early 20th century, the banyan evolved into the smoking frock or smoking jacket.