Hard Cider is the first alcoholic beverage I ever brewed. During the early to mid-60s I discovered that you could buy unpasteurized cider from the super market, leave it sit in your closet for a while, and viola! - something modestly alcoholic and somewhat drinkable resulted. I imagine our ancient ancestors, making juice out of their apples and storing it in a jug probably discovered hard cider in much the same way.
Apples originated in Kazakhstan and various migrating tribes carried the plant out from there into the Middle East and Europe. Apple seeds were also carried along various trade routes. The early apples were probably inedible but early on our ancestors learned how to ferment apple juice into cider. Julius Caesar tried cider for the first time in 55 BC during the Roman invasion of the British Isles. By the 9th century AD cider drinking is well established in Europe and William the Conqueror probably brought cider making and drinking traditions with him in 1066 with the Norman Conquest of England. Medieval Monasteries especially focused on cider using the sale of cider to help fund their work and these traditions probably account for the English, Norman and Spanish cider making traditions. Cider was popular in the American colonies and the new republic until prohibition which resulted in the destruction of many cider orchards. It is now regaining popularity as a "gateway" alcohol drink produced by large manufacturing concerns and also as a craft beverage as drinkers rediscover the European traditional ciders and as Craft Cider producers emerge in the US, recovering past practices, introducing European cider techniques and inventing techniques of their own. The world of cider is becoming as exciting as the world of craft beer and, for that matter Artisanal cheese and bread.
For reviews of books about cider and cider making, go here: Reviews of Cider Books