Apples continued their westward journey all the way to Northern Spain, where the regions of Asturias and Sagardoa in Basque have the perfect climate to grow them. This is called “Green Spain”.
When apples became made into cider instead of being eating is not clear, the Roman and Greek words for strong wine and cider are similar. Certainly it was not easy to make, considerable scare labour was needed to pulversise the apple and then extract the juice before fermentation could occur. With wine just treading the grapes with feet suffice! However cider was made here which the Asturians call Sidra.
Greek geographer Strabo describes sidra in his journey through Spain’s Asturia region in 60 B.C which would pre-date Julius Caesar’s discovery in the UK in 55BC. However, on further analysis it appears that Strabo the Greek was born in 64BC and, barring the possibility of him being a drunk literary toddler, it seems like any such reference in his works is second hand information he acquired from someone else at a later date.
His writings on the topic were likely compiled between 7BC and 23AD and some sources believe he never visited Northern Spain at all.
However Spain has a long history of apple cultivation and cider. From here it spread northwards to Normandy where the climate was marginal for wine