English puts an unusual amount of work on one short word. A shop can charge a fee. A prosecutor can charge a defendant. Cavalry can charge a line. A battery can charge overnight. A teacher can have children in her charge. Those uses feel like separate verbs and nouns that happen to share a spelling. They are not. Each of them still carries, in a more or less faded way, the idea of putting a load onto something that has to bear it.
A French load, not a native one
The origin of the word charge is a borrowing, not a Germanic inheritance. Around 1200 English took in both a noun and a verb from Old French, and from the Anglo-French of Norman courts and households. The noun meant a load or a weight, and also an imposition laid on a person. The verb, Middle English chargen, meant to load, to put a burden on or in, to fill something so that it would hold what had been put there. That physical sense is now mostly gone from ordinary speech. It survives in technical corners: charging a furnace with fuel, charging a firearm with powder, and in a few set phrases where the old load can still be felt.
The wagon under the verb
Old French chargier, to load or weigh down, did not invent the image. It continues Late Latin carricare, to load a wagon or cart. That verb is built on Latin carrus, a two-wheeled wagon. Roman writers treated carrus as a Celtic loan, a Gallic type of cart, from Gaulish karros, itself from a reconstructed Proto-Celtic word for a wagon. Comparative work takes the Celtic noun further back to a Proto-Indo-European form related to a root meaning to run. The same root is reconstructed behind Latin currere, to run, which later gave English course, current, and courier. In that older picture the wagon is the thing that runs.
The morphology is plain once the Latin pieces sit side by side. Carrus is the cart. The suffix that yields carricare makes a verb of putting something onto or into that cart. After the loading-verb had already passed into the Romance languages, speakers formed a second, later Latin verb on the same noun with the sense to convey by cart. That later formation is the source of English carry. Charge and carry are therefore cousins, not twins: two verbalizations of the same wagon, split by different sound changes in French. Another close relative is cargo, a doublet English later borrowed from Spanish and ultimately from the same Late Latin loading-verb. French charge, Spanish cargar, Italian caricare, and Portuguese carregar all keep the loading sense near the surface. Welsh car, Irish carr, and Breton karr keep the wagon itself.
How a burden became a price and a crime
Once English had a word for a load, the load did not stay physical. By the mid-fourteenth century the noun could mean a responsibility or a duty laid on someone, a burden of office rather than of grain. Take charge appears late in that century; in charge is recorded in the early sixteenth. The person or thing entrusted to someone else’s care, the young charge of a nurse or tutor, follows in the 1500s: the load has become a living trust. Money is a later thickening of the same metaphor. A cost, a pecuniary burden, is attested in the mid-fifteenth century; a price asked for goods or service by the 1510s. The verb to impose a burden of expense is Middle English. To fix or ask a price is much later, from the late eighteenth century, and to hold someone liable for payment, to enter a debt against an account, belongs to the nineteenth. Credit-card English is still talking about a load placed on a ledger.
Law took a parallel path. In the late fourteenth century the noun could mean an injunction or an order. By the late fifteenth it had the legal sense of an accusation, a claim laid on a person as a load of alleged guilt. A judge’s charge to a jury, the address that lays the law on the panel at the close of a trial, is recorded from the 1680s.
The military sense is newer, and the inner link is a little less certain. From the 1560s English uses the word for an impetuous rush upon an enemy. Historians of the vocabulary often connect that use to an earlier sixteenth-century sense of loading a weapon, as if the attack were a loaded force let loose; the connection is plausible rather than proven. The quantity of powder needed for one firing of a gun is attested in the 1650s, and the bugle call or order to attack in the 1640s. Heraldry kept another older picture: a charge is a figure placed on a shield, a load the field is made to bear.
What a battery still has in common with a cart
Electricity reused the loading metaphor with unusual fidelity. The verb, to fill with electricity, is recorded from 1748, the noun for an electrical quantity from 1767, in the decades when experimenters were learning to store force in jars and to speak of bodies as filled or emptied. A phone left overnight on a cable is doing what a thirteenth-century wagon was doing: taking on a load that it will later give up. Mid-twentieth-century American slang, a thrill or a kick, is a late informal echo of that stored energy. It is not needed to explain the older history, but it shows how readily English still treats the word as something that can be put into a person and then spent.
What is easy to miss is how little of the wagon remains in the modern word, and how completely the wagon still organizes it. French sound change palatalized the Latin c- before a into the affricate English writes as ch-. The Celtic cart that Latin borrowed, and that Latin then turned into a verb of loading, sits invisibly under a billing dispute, a cavalry scene, and a battery icon. Cargo kept a more obviously commercial shape of the same Late Latin verb. Charge kept the load, and then let every later century decide what counted as one.