Who invented trousers?

This time, it was not a Roman invention, but the Greeks relate it back to a powerful barbarian woman. According to 'ancient Greek traditions', 'the origin of this exotic attire' was referred to a series of different warrior queens of the East. In one of these legends, it is claimed 'that trousers and long sleeves were first introduced by Medea, the mythic sorceress-princess of Colchis who became the lover of the Argonaut Jason' (A. Mayor, The Amazons, Princeton, 2014).
In fact, trousers were more complicated to produce than a tunic or a toga. The latter were roughly a rectangle piece of cloth, draped and mostly fastened with pins and belt (as we can see them also in the wrap-around skirt of the Egyptians or the ancient and modern sari of Indian people).
Trousers, however, had to be invented, and they served a particular purpose - not far from their use in modern times, linked to riding, in antiquity they were produced for sitting on horses and fighting wars. Indeed, 'the earliest preserved trousers have been excavated in burials of horse-riding men and women in the Tarim Basin, dating to 1200 to 900 BC'. And in more recent excavations, 'two pairs of trousers fashioned more than three thousand years ago' were made from 'three pieces of wool with complicated zigzag and other woven patterns and featuring an inset crotch gusset for freer movement' (Mayor, 191). Again, it points to them having been used for sitting on the back of a horse.
What is interesting to note: They were not originally made for men, but used by both sexes, and it seems curious that what was once produced for hunting and warfare has been retained as the standard cloth for men today, even though there is now a general acceptance of trousers by women, while old tunica, skirts and sari are still not common as dresses for men.

Underwear at night time?

In a rather recent article, Neil Adkin asked 'Did the Romans Keep Their Underwear on in Bed?' (The Classical World 93 [2000], 619-20) and admits that, unfortunately, we have very scant evidence to answer this question. 'The Romans, unlike the Greeks, were prude' (ibid. 619 n. 7), if we follow what archaeology gives us, yet, there are a few hints in texts that are of some help. Martial 11.104.7-8 writes: 'a breast band and tunic and opaque band hide you, but no girl lies naked enough for me'. A. C. Dionisotti ('From Ausonius' Schooldays? A School-Book and Its Relatives', JRS 72 [1982], 83-125), concluded from Martial that 'night-clothes as such were not then current, but retaining (a little) underwear probably was'. Rightly, one did not trust this suggestion too much. And yet, Malcolm Heath ('Was Homer a Roman?, in F. Cairns and M. Heath [eds], Papers of the Leeds International Latin Seminar, vol. 10 [Leeds, 1998], 47-48; the passage of Eustathius in question is his commentary on Od. 1.121) pointed to Eustathius that a night sleep being fully naked 'was one of the Greek customs mentioned by Homer which was supposedly transmitted to Italy by colonists from Greece' (N. Adkin, p. 619-20). Adkin himself pointed to a wonderful story, told by Jerome (4th. century AD):
'Once, when a sudden earthquake in this province in the middle of the night awoke us all out of our sleep, you, the most prudent and the wisest of men, began to pray without putting your clothes on, and recalled to our minds the story of Adam and Eve in Paradise; they, indeed, when their eyes were opened were ashamed, for they saw that they were naked, and covered their shame with the leaves of trees; but you, who were stripped alike of your shirt and of your faith, in the sudden terror which overwhelmed you, and with the fumes of your last night's booze still hanging about you, showed your wisdom by exposing your nakedness in only too evident a manner to the eyes of the brethren. Such are the adversaries of the Church; these are the leaders who fight against the blood of the martyrs; here is a specimen of the orators who thunder against the Apostles, or, rather, such are the mad dogs which bark at the disciples of Christ.'
Jessica van 't Westeinde (Durham) who drew my attention to this passage, is working on Jerome, and it is clear that Jerome is talking about a southern province, hence Adkin's conclusion that we could draw from Jerome that Romans did not wear anything at night time, seems to neglect the temperature people are facing in Bethlehem or Jerusalem (although nights can be very cold in desert areas) at night might be different from what people experienced in say Rome, Milan, Bordeaux or York. Nevertheless, it is interesting that with the scant evidence we have, sleeping naked seems to have been known whereas no evidence to the contrary, as far as we know, has yet come to light.

Roman Clothings

All in all, Roman clothing was similar to the Greek.
The tunic was a piece of clothing for everyone. It was usually made up of two square woolen cloths which were connected at the shoulders and hung down to the knees. They were most commonly made out of uncolored wool and were therefore the color of oatmeal. - The tunic was held together at the waist with a belt. Those who were more well-to-do wore longer tunics.
The most famous piece of clothing for men was the toga, which was worn over the tunic. All freeborn were legally allowed to wear a toga. Usually, however, only men of the upper class – the “elected people” – wore a toga as a sign of an official mission: magistrates and senators wore them when they were carrying out their state obligations. But putting on such a toga was not an easy task - the material was folded and artfully draped over the shoulders! That is why they were often replaced with a cloak (pallium), but this was frowned upon in some circles.

The piece of clothing that was more popular than the toga in the end was the simple tunic, which was worn by men as well as women: a simple shirt, usually of white wool or linen made up of two parts sewn together. They were worn day and night. If you wanted to relax at home, you loosened the belt. In winter, people would wear up to four tunics layered on top of one another!
A special kind of tunic for women was the stole: it was favored in particular by matrons from the upper class and was characterized by a purple border on the lower hem. Of course women wore something like underclothes under the tunic: an apron and chest band. Women of the common classes were not allowed to wear stoles and probably didn‘t have the money for such elaborate clothing.
In the imperial period, the tunic was replaced by a cloak called pallium for men and palla for women. The cloak, which was taken from the Greeks, was easy to throw over the shoulders and usually went down to the ankles. The most popular color was purple.
If the weather was bad, there was also a poncho (paenula) with a hood, made of a rough woolen material. It was a funnel-shaped all-weather cloak without sleeves. Even simple folk could afford it!
In a society like that of the Romans, in which social position was put on display with status symbols and external signs, the discrepancy between rich and poor manifested itself in the clothing and in particular in the cloak. This was done with outward splendor, opposition, attracting attention, or a purposefully unkempt appearance – just like today!