Information about "exotic" sub-Saharan African and Asian animals flowed into medieval and early modern Europe through three basic pipelines: (1) a medieval genre of texts called bestiaries, which catalogued ancient authors' descriptions of animals real and mythical with an eye towards moral allegorical lessons for people (2) gifts from non-European courts to European kings and princes (3) European travelers, for many and diverse reasons, to the Near East, Central Asia, and eventually further beyond.

Bestiaries were fairly popular in the late Middle Ages, although they died off in the early modern era as observation and cataloguing interests began to surpass interest in fanciful moral lessons. It's important to keep in mind that each bestiary might have a different collection of animals, or invent its own description and lesson in order to serve the text's broader purpose (Richard de Fournival maybe did not quite think through the implications of a Bestiaire d'amour or the Bestiary of Love). In fact, giraffes seem to have been one of the rarer inclusions! (Although they are included in the 14th century manuscript of Der Naturen Bloeme that contains possibly my favorite piece of medieval art, this oyster who cannot handle the world right now). However, they're mentioned by 7C archbishop Isidore of Seville in his Etymologies, a text which was enormously popular among scholars in the late Middle Ages into the early modern era.

How far could this information have gotten? Well, the moral allegories underlying the bestiary genre were used first of all by medieval preachers in their sermons, so perhaps giraffes or "cameleopardi" (describing odd animals in terms of known quantities is a common pattern in European zoological writing, including in colonial America) made it into more popular consciousness that way. By the end of the Middle Ages, certainly in the era of print, manuscript and then printed bestiaries in vernacular languages would have entered the hands of better-off urban and noble lay readers as well. Scholars have pointed out that categorizations of animals from bestiaries and their sources show up in Shakespeare's writings, so their information was probably current in the bourgeois educated, maybe even the primary/grammar school world of Renaissance England.

By the late Middle Ages and considering a lay urban/noble audience, however, there was another much, much more likely source of information about giraffes: travelers. Well, one traveler, in particular, and a traveler who scholars now know did not exist as such. But the text bearing John Mandeville's name was THE secular bestseller of the late Middle Ages in multiple languages, even more popular than Marco Polo! The Travels reports:

There also be many beasts, that are called orafles. In Arabia, they are called gerfaunts. That is a beast, dappled or spotted, that is but a little more high than is a horse. But he has a neck twenty cubits long; and his croup and his tail is as of a hart; and he may look over a great high house.

"Mandeville"'s narrative was the most popular text for readers back home. However, actual western visitors to Greek (and later Ottoman, for that matter) Constantinople and to the courts of various Muslim emirs and caliphs in the Near East might well have seen a giraffe firsthand.

The keeping of menageries was a widespread practice for the elite around the tripartite medieval world, including China. Exotic animals were a show of power and wealth. They also made great diplomatic tools for rulers--11C Byzantine monk and scholar Michael Psellos noted that exotic animals were more popular state gifts than silk or jewels! Giraffes traveled up from the coastal and interior states in sub-Saharan Africa to the Near East, and from there to points further north and east (including, by the way, China).

Reports survive of giraffes in 9th century Cairo and early 10th century Baghdad; the giraffe in Constantinople when Humbert of Candida excommunited the Greek patriarch in Hagia Sophia church itself had been a gift to the emperor for helping Egypt through a famine. In the 1260s, Greek emperor Michael VIII had handlers walk his giraffe daily through a marketplace nearby the palace for exercise, where, we are told, it delighted all viewers.

Given the merchant and military traffic around the Mediterranean, these would at some point have included some Latin viewers for sure. Johann Schlichtberger, a German who wound up bouncing around various forms of captivity and enslavement across the Near East/Central Asia at the dawn of the 15th century, encountered in Persia a lot of animals he knew and one he didn't:

In this country are many elephants, and animals called surnofa (sic., surnasa), which is like a stag, but it is a tall animal, and has a long neck four fathoms in length or longer. It has long fore legs, and the hinder are short...There are also many parrots, ostriches, and lions.

Schlichtberger's discussion here suggests he expects his readers to know what is an elephant, a parrot, an ostrich; but a giraffe is foreign to them and can only be described.

Did actual giraffes make it to western Europe in the Middle Ages? Sure! (I mean, if 13th century England can have a polar bear that goes swimming for fish in the Thames...) But not nearly as often as you might think. Giraffes were hard to catch, harder to transport safely, and (tragically) even harder to keep alive at their destination. The exception was German/Sicilian emperor Frederick II, who had a giraffe that was reportedly such an important showpiece that he carted it around with him as he traveled from palace to palace. In the early 16th century, the sultan of Cairo presented a giraffe to Pope Leo X--small consolation for a Church about to split in two forever.

The most famous European giraffe before the grand and terrible 19th century where imperialism met naturalism, however, was a gift in 1486 to none other than Lorenzo de Medici. Florence already understood something about giraffes; a public feast and sporting event three decades before had featured a giant giraffe-shaped lure for lions. Although the giraffe had technically been a gift to the city to massage diplomatic relations with Mamluk Egypt, Lorenzo maneuvered to keep the giraffe in the Medici private menagerie for family status even more than civic.

However, as in 13th century Constantinople, he arrange to have the giraffe walked through the streets for exercise. According to contemporary reports, people used to lean out their second-story windows and feed it along the way! The giraffe was so important and so much the topic of conversation in the city that even cloistered nuns received special permission to leave their convents to view it in private settings.

Did the fama of the Florentine giraffe endure? Through the 16th and into the 17th century, numerous European "nature writers" and travelers describe giraffes. (Here's a 19th century historian throwing some polite shade on the reliability of most of them.) Granadan diplomat and author Leo Africanus, whom Europeans treated as the basic authority on all things natural/geographic about sub-Saharan Africa for a good long time, is probably the most famous of those.

Most interesting for current purposes, though, is probably the 1617 Itinerary of an English traveler named Fynes Moryson, sort of the prototype "get a grant to travel around and study things and publish" scholar. Moryson wrote:

[In Constantinople] I did see an elephant, called philo by the Turkes, and another beast newly brought out of Affricke, which beast is altogether unknowne in our parts, and is called sumapa by the people of Asia, astanapa by others, and giraffa by the Italians, the picture whereof I remember to have seene in the mappes of Mercator; and because the beast is very rare, I will describe his forme as well as I can...

So the knowledge of giraffes had survived at least among Italian scholars, and was one of the illustrations of distant lands on contemporary maps. But as we saw earlier, he still did not expect his readers to have the same ready mental image of a giraffe that in the way he could expect them to know an elephant.

"Europeans" absolutely knew about giraffes before the 18th century. Just how far down the scale of education, wealth, and travel experience that knowledge would have percolated is hard to sift out. The popularity of travel literature seems to suggest that many literature people would have encountered mention of giraffes at some point. But mass literacy is really a 19th century, even a 20th century phenomenon in the west (thanks, slavery and Jim Crow). Beyond that? I mean, we really shouldn't underestimate the strength of oral news and knowledge networks, but it's hard to know for sure.