The Anglo-Saxon word “deer” meant all wild animals in general, but it came to mean, in modern English, the one large wild animal that survived best in shrinking forest: the cud-chewing, horn-growing hoofed one.
The red deer is the one we see most in European cave drawings. It ranged from the Atlas Mountains in Africa to the Caucasus Mountains and Scandinavia. In medieval English, the stag of the red deer was known as a hart; with the boar, it was the most prestigious hunting quarry. At the shoulder, the average red deer is over four feet tall.
Roe deer (Cervus capreola) used to be called simply “roe” (Anglo-Saxon and Norse, ra). (The buck, of course, is the “roebuck” of catalog sales fame.) They don’t have white spots and adults may, at the shoulder, be as small as two feet high. Bucks grow small antlers with usually no more than three points. Roes ranged all over Europe and Asia.
The European fallow deer (Dama dama) is native to Turkey and the Mediterranean region, while the Persian fallow deer (Dama mesopotamia) was in Iran and the Middle East. Fallow deer bucks are only about three feet tall at the shoulder, but their antlers look more like elk or moose. Most of them have a brown coat with white spots, like North American deer fawns.
When European nobles went hunting, they chased the hart and the roe. The great thing about hunting these large animals is that they didn’t aggressively attack humans. Hunting parties could include ladies and take place on beautiful summer days, unlike boar hunts. We still use the word venison for deer meat, but they additionally called the process of hunting venery. (Confusingly, venery also means the pursuit of sexual pleasure.) Packs of dogs were trained to flush animals out of hiding and corner them for the humans to kill.
As forests shrank, nobles maintained special parklands for hunting deer. Parklands had ditches around to serve as fences; a deep and wide enough ditch discouraged deer from migrating out. A parker lived in a cabin in the forest and kept track of the herd. Trees could be coppiced, that is consistently cut and pruned so that they created many shoots instead of one trunk. (Peasants liked to coppice trees anyway, since that way they had more pliable branches for weaving into wattle fences and walls.) If the herd was growing too large for the natural greenery on the parkland, parkers might just spread hay.
Norman lords in England refused local residents permission to come onto their parklands, even if they were just in search of firewood or trapping hares. The Forest Laws were a great source of grievance and gave rise to the Robin Hood legends; Sherwood Forest was certainly one of the large set-aside hunting grounds. Deer had too much valuable meat for people to give up, but poachers needed fast ways to get the animals and get out. They might drive deer into nets or pits.