What's the difference between i.e. and e.g.?
late 13c. (in Anglo-Latin); c.1200 as a surname, "messenger, envoy," from Anglo-French heraud, Old French heraut, hiraut (12c.), perhaps from Frankish *hariwald "commander of an army," from Proto-Germanic *harja "army" (from PIE root *koro- "war;" see harry) + *waldaz "to command, rule" (see wield). The form fits, but the sense evolution is difficult to explain, unless in reference to the chief officer of a tournament, who introduced knights and made decisions on rules (which was one of the early senses, often as heraud of armes, though not the earliest in English).
late 14c., "to sound the praises of," from herald (n.). Related: Heralded; heralding.