Originally
There is no clear texts that would tell when Sake was invented. Chinese alcohols which some are made from Rice as well predate written history. On Kojiki (oldest written chronicle in Japan from year 711 ) Alcoholic drinks are mentioned, it is suspected that Sake came to be around the same time as Kojiki. It was usually used the same way wine was around that time, for religious ceremonies and for enjoyment by rich and poor. Sake just as wine is till today used in religious ceremonies and different festivals but not as much as before.
Present
Although there are some sake breweries in America and Europe, let's be traditionalist and focus for now on the sake from Japan. There are a few prefectures especially famous for sake production such as Niigata, Hyogo, and Hiroshima. But in fact, all prefectures in Japan except Kagoshima produce sake (even tropical Okinawa). There used to be a distinct type of flavor per region, but in recent years production has become more and more diverse and now it has become difficult to pin down a distinct flavor per region. Rather, sake drinkers choose depending on individual brewer or for instance, pureness. Even though sake drinking has become more popular around the world, the amount of sake breweries in Japan has declined since 1975 by almost half.