I know apples have been cultivated for thousands of years but were they usually as large and well-developed as modern apples you can buy in the store? If not, when and how did they become like that? I know when I pick an apple from a single tree someone has in their backyard it's always much smaller than store-bought apples. Is that closer to what most historical apples would have been like?
Alexander the Great is reported to have brought a certain type of apple back to Greece and it's passingly mentioned that he threw an apple at someone during a banquet. I just wonder how those apples would have differed from modern apples for example.
There are a huge number of apple cultivars. It's a very easy tree to cross-breed, compared to some other fruits, and new varieties are still being created.Though thousands have been developed and lost, some quite early ones are still being grown: the Lady Apple dates back to the early 17th century, if not before. The newer breeds are not necessarily larger: though some later ones are quite big, like Pound Sweet ( 1834) many newer crab apples varieties are small, like the Centennial Crab ( 1957)
The origin of apples seems to be Kazakhstan, and the oldest one seems to be Malus sieversii. You can see photos and useful research about it here. It's not that different in size and appearance from some other newer breeds. I realize that it's Wikipedia, but the linked source notes are pretty good, including this in-depth article on the genetic history of European malus domestica.