Motivation
I am currently researching the electoral redistricting process, and I wondered when districting (as opposed to at-large systems, and slightly different than simple local representation) came about in the first place, and who invented the ideas.
The Questions:
Splitting up the main question into levels of both qualification and implementation. The answers can be from any level of government.
A1. When was the concept of an electoral district for local representation first invented or thought of?
A2. When was the concept of an electoral district for local representation first implemented?
B1. When was the concept of an electoral district as a distinct unit with its own borders (as opposed to simply local representation of a pre-existing town, county, or neighborhood) invented?
B2. When was the concept of an electoral district as a distinct unit with its own borders first implemented?
C1. When was the concept of an electoral district as a unit with malleable borders invented?
C2. When was the concept of an electoral district as a unit with malleable borders first implemented?
(I presume that the question only makes sense for republics or democracies, but I am willing to listen to other forms of implementation.)
Current Knowledge
A2
The early English (later, British) Parliament had proto-constituencies, according to the Wikipedia article "Unreformed House of Commons":
"Representative men summoned by emerging custom, thus convention, fixed upon two to be selected by each (Parliamentary) borough and two knights of each shire (county)."
This is at least local representation in a parliament.
B1
The Federalist Papers speak of at least prototypical districts. Federalist #56 states,
"Divide the largest State into ten or twelve districts, and it will be found that there will be no peculiar local interests in either, which will not be within the knowledge of the representative of the district."
Further on, it reads,
"The representatives of each State will not only bring with them a considerable knowledge of its laws, and a local knowledge of their respective districts..."
The mention of an uncertain (and small) number of districts would be unnecessary if it went lockstep with existing borders; this seems to be evidence for a new entity.
(The nascent attempts at British parliamentary reform in the mid-18th century (see again Wikipedia, "Unreformed House of Commons") only seem to decide which towns "count," and not the connection with specific places. I do not think it counts as an answer to B1.)
B2/C1
The Federalist Paper #59 mentions districts already in place for state legislatures in the United States:
"The districts in New Hampshire in which the senators are chosen immediately by the people, are nearly as large as will be necessary for her representatives in the Congress. Those of Massachusetts are larger than will be necessary for that purpose; and those of New York still more so."
Hence, at least on the state level, there were already districting systems in place in some states during the Articles of Confederation. The proposal to change the size of the districts from the preexisting ones also suggests some support for C1.
(If one insists on the national level, according to the Wikipedia page "1788 and 1789 United States House of Representatives elections", South Carolina held a district election for their first U.S. Representative in November 1788.)
(Across the pond in Great Britain, if I understand the answers to History.SE Question 33432 correctly, English (later, British) Parliamentary Constituencies were not greatly malleable before the Parliamentary Boundaries Act of 1832, and were firmly tied to existing towns/counties/universities/other institutions. Without further data, I am unsure that they are an answer for B2; they certainly do not furnish an example to C2. )
C2
Engstrom (2013) reports (p. 28) that "one can easily find examples of district manipulation well before 1812 and Gerry's map," implying malleable borders, but does not give particular times to the examples he mentions, talking only about aggregate effects in the 1802-1820 time period. Hence, the answer to C2 is "well before 1812."
(Butler and Cain (1992) note (p. 118):
"During the nineteenth century in Europe and the self-governing colonies around the world the drawing of boundaries was left to the legislature almost everywhere."
Malleable boundaries were in the norm in the 19th century, but that does not give earlier instances.
Print References and (Other) Online Links
Butler, David, and Cain, Bruce. Congressional Redistricting: Comparative and Theoretical Perspectives. New Topics in Politics Series. New York: Macmillan Publishing Co., 1992.
Engstrom, Erik J., Partisan gerrymandering and the construction of American democracy. Ann Arbor: U. Michigan Press, 2013. JSTOR Open-access link at https://www.jstor.org/stable/j.ctt1gk086k
FairVote.org, History of Creating Congressional Districts, accessed 27 Oct. 2022, http://archive.fairvote.org/?page=1724