<p>Rohan, atleast in the movies, resemble various germanic tribes, but with warhorses. Their swords have hilts that resemble various viking age cultures and, funnily enough, bronze age cultures. The horse mastery however more resemble huns/medieval knights.
</p><p>Gondor, the armours mostly resemble italian armours of the high-late middle ages, but with a higher emphazy on dismounted combat, like the english. Their rangers could be any medieval uprising/bandits. The architecture seems kinda ancient roman, with a mix of renaissance north italy.
</p><p>Hobbits, clothing, furniture, and food, could be english/german 1700-early 1900.
</p><p>Elves, basically hippy communes. Everyone is just doing their own thing, hanging around, dancing, singing, wearing dresses, and spending unhealthy amounts of time perfecting their hobbies.
</p>