In the decades following the Peace of Westphalia the foundations of what many consider modern diplomacy were formed. These foundations have been a popular topic for many historians, and extensive work has been made on Diplomatic Theory, and the ideals of what a diplomat should be within the field of new diplomatic history. However, the practices, performativity and persona of the diplomats still needs a deeper level of study, which is the main purpose behind this thesis. This thesis investigates the diplomatic practices in the early 18th century through the correspondence of a controversial Swedish diplomat by the name of Carl Gyllenborg. The controversy surrounding him was because of his involvement with a Jacobite plot to restore the house of Stuart on the British throne, which ultimately failed, called The Swedish Plot. By analysing his correspondence with another ambassador, Erik Sparre, the institutional, material and communicational practices of an early modern diplomat emerge.  What this thesis shows is the way Gyllenborg navigated both the expectations and obstacles inflicted upon diplomatic practices. Some of the obstacles he faced was neglect from his sovereign, which included a lack of a letter of credence, being considered an enemy at his assigned court, and lacking finances to fund his life as an ambassador. He managed to navigate these although lacking the necessities stated by Diplomatic Theory. Gyllenborg’s story brings too light the complexity of early modern diplomatic life which has been lacking in previous research.