military

Frontinus Compiles Strategemata on Siege Methods

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Around 95 CE, Sextus Julius Frontinus gathered siege stratagems that made deception and engineering partners. Organized by problems—water, supplies, morale—his Strategemata shows artillery as one tool among many [7]. The creak of a hidden siphon mattered as much as the snap of a scorpion.

What Happened

Frontinus, twice consul and manager of Rome’s aqueducts, thought about flows—of water, of information, of fear. In the Strategemata he wrote a handbook of tricks arranged not by units but by the problems besiegers and defenders face. The result is a tour of practical cunning where engines and earthworks mix with diversions and ruses [7].

He includes the obvious with the unexpected. Under the heading of water, he notes how cutting or diverting supplies can do what rams cannot. Under provisions, he offers ways to make a garrison feel its stomach sooner. He catalogs decoys and fake deserters because a sally into an ambush can break a siege faster than a tower can climb it [7].

Artillery lives in this world as a partner. A battery of ballistae can pin wall-crews while sappers drive a mine forward; onagers—later famous for their savage kick, “onager” in Ammianus’ words—can batter a gate while the real strike comes from a hidden tunnel [3][7]. Frontinus’ emphasis on method over mechanism makes such combinations intelligible: choose the lever that fits the problem.

Set the scene at a Gallic oppidum years after Vellaunodunum. The Romans erect vineae—covered sheds—whose pale wicker sides bob like boats, and wheel forward rams. The thunk of the aries against masonry sends powdery dust into the air. Behind the sheds, crews ready scorpions, the string’s snap masking a miner’s tap below. Somewhere outside the lines, a small detachment feigns a foraging party, drawing defenders into a kill zone. Frontinus would count each piece as a stratagem [7][5].

His administrative mind carries across the empire’s map. In Britain, at Londinium, standard bolt heads in museum collections testify that the supply side of stratagems kept pace with the tricks [14]. In Jerusalem, Josephus’ “the stone cometh” shows a defender’s countermeasure—watchmen calling arc and color, white stones visible even at distance [2]. Frontinus would file that under “know what your enemy sees.”

He writes not as a theorist but as a collector, assembling the Roman habit of turning walls into solvable problems. Caesar’s lines at Alesia are the large-scale version; Vitruvius’ ninths are the workshop version [5][1]. Frontinus stands between, enumerating the median tactics that make both work day to day: the small lies, the timed sorties, the way a line of palisades and a pit of lilia can make an onager’s stone matter more.

It’s a quiet book, but it hums with the creak of ropes and the soft thud of shovels. Like an aqueduct, it delivers force where it’s needed with as little loss as possible.

Why This Matters

Frontinus’ Strategemata reframes siege warfare as a series of fixable problems. That framing integrates artillery naturally: engines become force multipliers for deception and engineering instead of solitary solutions [7].

The text embodies the theme of speed and fieldworks as weapons because it shows how earth and timing set the conditions under which rams and ballistae can do their work. Caesar’s two-day ring at Vellaunodunum and his double lines at Alesia look like stratagems in Frontinus’ taxonomy—time-bound choices that shape outcomes [20][5].

In the long arc, the Strategemata’s habits survive into late antiquity. Ammianus’ descriptions of onagers and rams assume a world in which defenders and attackers try to outguess each other within engineered spaces [3]. Vegetius’ lists formalize the same, embedding engines “behind the heavy infantry line” and assigning them per century and cohort [4].

Historians value Frontinus for his categories. They reflect an institutional memory: Rome did not just train men; it trained minds to classify problems and recall solutions. That memory kept mines and engines complementary from Veii through the 4th century [6][7].