I recently fielded a question from a woman for whom I provided a Braintree MA birth record: "Joshua Spear the son of John Spear Terts. and Mary his wife born May 11th. 1753." [Records of the Town of Braintree, 1640 to 1793 (Randolph, MA: Daniel H. Huxford, 1886), p. 804]. The woman wrote back asking what "Terts." meant. The short and simple answer is that it is the abbreviation for "Tertius," the Latin ordinal meaning "third." That answer, however, begs the real question of why this man was called "Tertius."

     Those new to genealogy may be puzzled when they see old contemporary records refer to someone as "Junior," "Tertius" (or "III" or some allied term) when that person's parent has a different name (as in the example above - note that women, as well as men, are sometimes designated in this way, but to simplify phrasing I will use men as examples in the balance of this article). The answer is that before the early 1800s the terms "Senior," "Junior" and "Tertius" (or "III") did not have the same meaning that they do today. Middle names did not begin to appear in American records until the middle of the eighteenth century, and did not become common until the early nineteenth century. Before then Town Clerks required some way to distinguish between two or more men with the same name who lived in the same town.

     The system geneally used for, say, two men named John Smith in the same town, was to designate the elder as "John Smith, Senior" and the younger as "John Smith, Junior." If there were more than two men of that name the successively younger men would be designated "Tertius" (third), "Quartus" (fourth), "Quintus" (fifth) and so on. Anyone who graduated from high school before 1970 should recognize the last three terms as Latin ordinals. As a matter of fact, some clerks used the ordinals "Primus" and "Secundus" rather than "Senior" and Junior." The use of "Senior" and "Junior" did not imply relationship, only age.

     The point where this gets truly confusing comes when the man called "Senior" died or moved out of town. After that point the man previously called "Junior" became "Senior," "Tertius" became "Junior," and so forth. Thus a man might be called "John Smith, Tertius" in his birth record, "Junior" in his marriage record and "Senior" in his death record. It sometimes requires considerable research into a town's records outside of its vital records (and other sources such as probates and deeds) to discover exactly which individual is meant by "Junior" in a particular record.

     After middle names became common this practice fell into disuse, and the terms "Senior," "Junior," "III" and the like assumed the connotations of relationship which they bear today (such as "George Hamilton, IV"). The upshot is that, prior to about the mid-1800s, look very carefully when you see two men of the same name in the same town designated as "Senior" and "Junior" - although they may be father and son, it at least as likely that they are not (they might be uncle and nephew, even more distantly related, or totally unrelated).

     For a companion article addressing confusing terms of relationship such as "Uncle," "Brother," "Father" and the like, see "When is an Uncle Not an Uncle?". For a classic dissertation about these terms and others, see George E. McCracken, "Terms of Relationship in Colonial Times" in The American Genealogist, 55 (1979): 52-54.