Terms such as envoy, emissary, messenger or negotiator were often used by early modern diplomats and bureaucrats to designate different types of diplomatic agents charged with temporary missions. Despite the gradual adoption of the model of the resident ambassador and formation of a professional diplomatic corps throughout the sixteenth and seventeenth centuries, the financial costs of maintaining a permanent embassy in a foreign court, as well as reasons of political strategy and symbolic communication, led many polities to preserve some the ad hoc diplomatic practices that predominated between antiquity and the late fifteenth century. Indeed, the diplomatic terminology inherited from Roman and medieval eras persisted in the designation of temporary agents who were regularly identified with titles such as nuntius, orator, procurator, legatus or missus. The fact that many of these shared similar functions with resident ambassadors contributed to a terminological confusion which lasted well into the early eighteenth century. François de Callières, the author of the influential De la manière de négocier avec les Souverains (1716), for instance, did not differentiate between envoy and negotiator when describing the function of the ambassador.
In Elizabethan and Stuart diplomatic correspondence, ‘envoy’ and ‘ambassador’ were often interchangeable terms. The persistence of Latin as a diplomatic lingua franca throughout most of the sixteenth and seventeenth centuries favoured the use of terms such as legatus or orator to identify a series of English diplomatic agents who were appointed to temporary missions. Nonetheless, the English translations of the summaries of the credentials and letters produced by Elizabethan and Stuart diplomats and bureaucrats frequently resort to the term ‘envoy’, which, according to the Oxford English Dictionary, originates from the French envoi, describing the action of sending something. The association between the term ‘envoy’ and the transmission of messages is well illustrated by references to envoys in the Elizabethan and Jacobean diplomatic correspondence written in English. On 19 February 1569, for example, Christopher Mundt wrote from Cologne to William Cecil that ‘certain great men would wish her Majesty to send an envoy with congratulatory messages, and so to renew the old amity and confederacy with the Protestant princes’. In June 1580, Elizabeth I hoped to impede the acclamation of Philip II of Spain as king of Portugal, and planned to send an unnamed envoy to Lisbon to establish contact with the Dukes of Braganza, who also claimed the Portuguese throne, ‘because we could by no other means, either from their ambassador resident here, or otherwise, understand certainly the state of their affairs, we resolved for our better satisfaction to send an express messenger to them’.
The envoy’s role as an extraordinary messenger, as in the instance above, could leave him free to operate in some ways beyond the strictures and formal frameworks of diplomatic hierarchy, largely due to that emphasis on the successful completion of an immediate task — frequently the transmission of crucial information — rather than long-term diplomatic function. Tellingly, it is this freedom that the literary form of the ‘envoy’ would begin to exploit from the fourteenth century onwards, when it first appeared in English literature and was popularised, in particular, by Geoffrey Chaucer. It has been well-established that English writers such as Chaucer and his contemporaries adopted the form of the poetic 'envoi' or 'envoy' from the medieval French tradition of concluding a ballade with a final stanza dedicated to an addressee, often with a moral message. However, in their hands, the English poetic 'envoy' turned into a significantly more flexible vehicle. In poems such as Chaucer's fourteenth-century 'Lenvoy to King Richard' at the end of his poem, 'Lak of Stedfastnesse,' or John Lydgate's moral envoys in The Fall of Princes (1431-48), the traditional humility topos of sending one's text out in the world was combined frequently with messages of instruction, advice, and sometimes sharp critique directed towards aristocratic addressees. Later, in a rapidly developing print market, Edmund Spenser's Shepheardes Calendar (1579) would split up the envoy into multiple entities, including 'To his booke,' the poem dedicating the text to Sir Philip Sidney, and a final envoy sending it forth among a wider, general readership.
Within actual diplomatic practice, one of the many results of the early modern economic, cultural, and demographic interconnections between different territories in Europe and beyond was that diplomatic contact often relied on individuals who were involved in transnational trading, intellectual, religious or artistic networks. Envoys tended often to be individuals engaged in cross-cultural activities outside diplomacy, such as merchants, clergymen, physicians, travellers, or factors. Thanks to their language skills, personal networks, and knowledge of local institutional apparatus, these individuals were able to carry out specific missions as intermediaries. As a facilitator of communication, the envoy was therefore an individual who had or developed the capacity to move between contexts that were both ‘local’ and ‘global’. It was this element of mobility that allowed envoys to further communication between different political systems and actors. Indeed, Tudor and Stuart monarchs often recruited foreigners as envoys or messengers such. Matias Becudo, for example, a former Portuguese Franciscan friar, was dispatched by Elizabeth I as an envoy to Marrakech to persuade the Moroccan emperor al-Mansur to grant the English a seaport in Morocco thanks to his knowledge of Arabic, Portuguese and Spanish. The Protestant Swiss refugee Stephen Le Sieur, who thanks to his knowledge of French and German was dispatched as envoy or messenger to several diplomatic missions to the German principalities, ended up appointed by James I as resident ambassador to the Holy Roman Empire, Florence, and the German Protestant princedoms, as well as being rewarded with naturalization in 1620.
Although not natural subjects of English monarchs, these diplomatic agents were usually recognised and appreciated as legitimate delegates of the English crown. The Genoese Horatio Palavicino, who served Elizabeth I in a variety of special diplomatic missions with the title of ‘envoy from the Queen of England’ in Germany and France, was praised in 1586 by the Elector of Brandenburg as a true representative of Elizabeth’s royal dignity for ‘[she] diligently put before him her benevolent and favourable good-will, and her views concerning the new disturbances in France’ and presented ‘her friendly greeting and declarations of kindness’. This acceptance of a foreigner messenger as legitimate representative of an English monarch suggested that, although not vested with the symbolic and political privileges that were being gradually associated with resident ambassadors, envoys and other emissaries, even if ‘stranger’ or ‘aliens’, enjoyed a honourable status reinforced or made acceptable by the terminological and legal confusion surrounding the definition of different diplomatic posts. John Northleigh, for example, who did not made a clear distinction between the functions of ‘ambassador’ and ‘envoy’, argued that the ‘Character of an Envoy is the most immediate representation of the King, and every Act of his, but another of the State’.
However, by the end of the seventeenth century, the employment of foreigners as diplomatic agents became more problematic. The development of a professional diplomatic corps, and the sensitivity of the subjects dealt with by diplomats, encouraged the perception that diplomatic service should be an exclusive of English nationals. The ascension of William of Orange to the English throne and apprehension of growing Dutch influence on the English state led to fear that the king could ‘appoint a Dutch Man Ambassador or Envoy to any Court in Europe’ since this would lead to ‘Sacrificing the Concernments of England, in that Court and Country, to the Pleasure and Profit of the Hollanders'.
The term ‘envoy’ was frequently applied to diplomatic agents of non-European polities. The English East India Company (EIC) and the Levant Company, for example, encountered polities with highly developed diplomatic systems with their own complex protocols, practices and conceptual frameworks. While European ambassadors and envoys enjoyed a privileged status inspired by the Roman law of nations, in the Ottoman Empire, Morocco, Savafid Persia or Mughal India, English and other European diplomatic agents found different notions of ambassadorship predominated, which granted a limited legal and political status to diplomats. John Chardin, in his account of his travels in Persia and India, explained to his readers that ‘the Persians make no distinctions between Embassadours, Envoys, Agents, Residents, &c. but still make use of the word Heltchi, which comprehends all’. English diplomats stationed outside Europe therefore had to deal with diplomatic systems based on different notions of ambassadorship which required almost permanent negotiation with local authorities on the effective status of English diplomats. Challenged by diplomatic systems with different categories of diplomatic agents and with a preference for temporary missions, the English and their European rivals in Asia and Africa frequently used the term ‘envoy’ as the immediate correspondence to figures such as the Persian Heltchi mentioned by Chardin. John Ovington, for example, mentioned that ‘a Chinese Madarine, who arriv'd at Suratt in the quality of an Envoy from Limpo’, and Francis Brook transcribed a proclamation signed by King William and Queen Mary on an ‘ Offer from the Emperor of Fez and Morocco, by his Envoy sent hither to Treat about a general Redemption of all the Engllish that are his Slaves’.
As Jonathan Burton observed, the ‘failure to consider how notions of an embassy or an ambassador can be specific to particular cultures’ often led to an undervaluation of the diplomatic initiative for non-European polities. Sir Thomas Roe complained that the Mughal court was a place ‘not fitt to keepe an  Confronted with a system of diplomatic exchange based on a different political conceptual framework and symbolic language, Roe defined Mughal diplomatic practices as ‘affronts and slavish customes’ that undermined the function and status of an ambassador. Indeed, the widespread use of the term ‘envoy’, particularly to African or Asian diplomats, suggest a minorization of these societies and their political and intellectual systems.