What is "prorogatio"

In the constitution of ancient Rome, prorogatio was the extension of a commander's imperium beyond the one-year term of his magistracy, usually that of consul or praetor. Prorogatio developed as a legal procedure in response to Roman expansionism and militarization; the number of annexed territories and theaters of operations outgrew the number of elected officials available to take on military and administrative duties.

Although in theory prorogation fostered continuity under an experienced commander with "expert knowledge of local conditions," thereby increasing the chances of victory, in practice politics, often motivated by the ambitions of individuals, decided whose commands were extended. Sometimes men who held no elected public office — that is, private citizens ( privati) — were given imperium and prorogued, as justified by perceived military emergencies. By the Late Republic, prorogation of provincial assignments had become the norm; by enabling individuals to accumulate disproportionate military power and wealth, the practice contributed to the breakdown of constitutional checks and balances and to the civil wars that led to the collapse of the Republic.