Diplomat in 1626: Richelieu creates the first foreign ministry

Do diplomats need to speak multiple languages? Almost always, though requirements vary. Most foreign services require or strongly reward fluency in at least one language beyond the diplomat's own, and postings to non-English-speaking countries typically come with paid language training beforehand — the US Foreign Service Institute, for instance, runs immersive courses lasting from months to nearly two years for the hardest languages before an officer ever arrives at post.

In the United States it is the Foreign Service Officer Test, a written exam covering job knowledge, English usage and a personal narrative, followed for those who pass by a full-day oral assessment simulating real diplomatic scenarios. Combined pass rates historically run from the low single digits to around six percent, making it one of the more selective entry exams into any government career.

Diplomatic immunity is legal protection, codified in the 1961 Vienna Convention on Diplomatic Relations, that shields accredited diplomats from arrest, prosecution and most taxation in the country where they serve, and makes an embassy's premises, archives and diplomatic bag inviolable. It exists so a host government cannot pressure a foreign government by threatening its representative, not as a personal privilege.