How did travellers travel the world in the 16th century? Was there visas?

This subject has become of greater interest to me as I begin to study global history more generally. Here is my take on question:

First, at this time some people travelled for leisure. Richard Hakluyt's Voyages is from this period after all. However, generally speaking most did not. Most people at this time travelled due to displacement, work, and diplomacy. As such, what documentation there was, dealt with this type of travel.

Adam McKeown has written an incredible monograph about the history border control, migration, and the emergence various technologies of border control, such as the passport or travel visas. McKeown essentially argues that modern border controls and technologies surrounding them are the byproducts of the rise of nation-states and globalization, which he looks at as coterminous phenomenon.

McKeown rightly points out that by the 16th century, Europe and European thinkers were increasingly concerned over freedom of movement. Largely these concerns were related to trading opportunities in Asia and the Americas that emerged as a result of European colonial expansion during this period. 16th century Spanish theologian Francisco de Vitoria, for example, argued that Natives in the Americas in fact held the same dominion over their lands as Europeans did. However, if they did not grant Spaniards the "natural" right of movement and mobility through their lands, then this was cause enough for war: "When all things were held in common, everyone was allowed to visit and travel through any land he wished. This right was clearly not taken away by the division of property."

So up until the nineteenth century, to a large degree, the right to mobility was recognized throughout Europe as a God (capital G for them) given right. Its important to note that national borders were far more malleable and murky at this time then we know them to be today. Because of this, short distance and season travel often occurred within informal networks of merchants, craftsman, labourers, and family. Travel like this was often regulated through guilds or through ethnic or familial diasporas. Thus, successful and safe passage within these networks required some sort of deference to their norms, values, and institutions. In this regard, these informal travel networks self-regulated themselves to a degree.

What is important to note that within these networks it was very easy to tell who belonged and who did not from the types of tools, clothing, or knowledge they carried with them. Monks or missionaries held knowledge of classic languages, for example. Because of this, travel documents were more or less letters of formal introduction as much as they were "identification". They outlined the traveller's status (master of a ship, caravan etc.) and detailed the traveller's accompanying goods, companions, and clothes. Not all travellers had such formal letters. For many, bills of sale were used as travel documents as well. However, what is certain is that there was no standardized travel documents like we have today, simply customs informed by the intellectual discourse of the period.

So, what we have in 16th century Europe is an intellectual undercurrent, accompanying global colonial expansion, stressing a "natural right" to free mobility. Yet, the 16th century world is a scary place, so these movements occurred within informal networks, facilitated by a collaboration of state and private actors (and indeed at this time the two are often blurred). Travellers did not have "visas" per say, but were identified in other ways. What is clear is that the identification systems of the 16th century required more interpersonal relationship and connections then modern border controls like the passport or the visa.