Two histories behind one spelling
In current English, ring is a circular band of metal on a finger, a boxing arena, a closed group of people, the sound a bell makes, and a telephone call. Those uses do not share a single pedigree. The circular senses and the sounding senses are two native Germanic inheritances that only later look identical, once Old English dropped the initial h- that both words once carried.
The origin of the word ring is therefore two stories that happen to share a spelling, not one tidy line from a single ancestor.
A native word for a circle
The noun that means a circlet, hoop, or round enclosure is inherited, not borrowed. In Old English it appears as hring, covering a metal band worn on the finger, a link in mail armour, and almost anything circular. Other early senses include a round group of people or birds, the horizon as a circle, and jewellery for the arm as well as the finger. The word is recorded before the twelfth century.
From there the path is straightforward Germanic descent. Middle English has ryng. Behind Old English stands Proto-West Germanic hring and Proto-Germanic hringaz, reconstructed as something curved or circular. Close relatives still look familiar: Old Norse hringr, Old Frisian hring, Dutch ring, German Ring, Swedish ring. Finnish rengas is a Germanic loan, not a true cognate. English rank is a more distant relative of the same stock, entering through Old French from a Frankish form of this hring- word.
The Old English hr- cluster is morphology worth noticing. The initial h was still pronounced early on and later lost, which is why modern ring no longer looks like hring. The same loss affects the sounding verb, so two different Old English words now share one modern form.
An older root, and a real uncertainty
Etymologists usually take Germanic hringaz as a nasalized extension of a Proto-Indo-European root meaning to turn or bend, written (s)ker- or (s)krengʰ-. That would tie the English noun to the idea of something bent into a curve. A Slavic family of words for circle, including Russian krug and Polish krąg, is often cited as the nearest non-Germanic match.
That deeper reconstruction is not settled. The only sure attestations sit in Germanic and Slavic, and the reconstructed shape sits awkwardly against a usual Indo-European constraint on which consonants can co-occur in a root. The form may therefore be late, post-Indo-European, or taken from a source that is no longer identifiable. The Germanic and Slavic comparison is solid; a neat Proto-Indo-European story is not.
How the circle took on new jobs
The physical circlet never disappeared, but English kept attaching social and spatial jobs to it. By about 1200 the finger band is already a token of marriage or betrothal. Ring finger is older still: Old English already had the compound hringfingr, and related compounds exist in other Germanic languages.
A prize-fighting ring is attested from the early fourteenth century. It did not start as a square of ropes. Contests were held in a space cleared among a circle of onlookers, and the word named that circle before it named a built enclosure. From that use, the ring could mean boxing itself by the late eighteenth century. The same spatial idea later yields a circus ring.
From the late sixteenth century the noun can mean a number of things arranged in a circle. Tree rings, the annual growth bands, are recorded from the seventeenth century. Fairy ring for a circle of mushrooms appears in the 1620s. By 1829 ring can also mean a combination of people pursuing a shared, often commercial or political, object; later English applies that sense to crime. Chemistry took the circle as a closed chain of atoms. Those technical senses are extensions of the circular noun, not new borrowings.
A verb meaning to put a ring on something or to encircle it is formed inside English from this noun. Late fourteenth-century evidence covers attaching a ring; around 1500 the sense to make a circle around something is in place. Oxford’s earliest cited date for this conversion is 1446. Old English had already used prefixed verbs such as ymbhringan and behringan, both meaning to surround, so the later unprefixed verb sits on older native ground.
The other ring: sound, not shape
Separately, Old English had hringan, a verb meaning to cause a bell to sound, and also to announce or celebrate by that sound. This is the ancestor of rang and rung. It comes from Proto-Germanic hringijaną, with cognates in Old Norse hringja, Swedish ringa, and Middle Dutch ringen. The usual judgement is that the verb is imitative: it copies a metallic clang rather than describing a circle.
It began as a weak verb. Strong forms of the sing type spread in early Middle English, which is why modern English has ring, rang, rung instead of a regular past. An intransitive use, of an object that gives a resonant sound when struck, is in place by about 1200. Places can resound by about 1300. Ears that buzz after noise are recorded by the late fourteenth century. A specialised test of coins, to sound them for genuineness, appears around 1600 and later feeds phrases such as to ring hollow.
Telephone English grew on this verb, not on the circular noun. To ring someone up is attested by 1880; a telephone call as a noun appears around 1900. British English still uses give me a ring for a call, which is this family, not jewellery. Stage English belongs here too: to ring a curtain up or down, from the 1770s, comes from signalling the scene change with a bell.
One specialised noun sense is a later overlay. In algebra, a ring is a set with two operations meeting a defined list of laws. The mathematical use follows German Ring, introduced by David Hilbert in the 1890s; English takes the term in the early twentieth century. The metaphor is the closed group, so it still sits with the shape-word, but it is a scholarly borrowing of a cognate, not a medieval English sense.
A practical way to keep the histories apart is to watch the past tense. Ringed the building is the circle verb. Rang the bell is the sound verb. Homophony after the loss of Old English h- conceals that split. The deeper Indo-European root of the circle-word may never be fully recoverable, but the split itself is not in doubt: one native noun for a bent or closed shape, and one native imitative verb for a metallic sound.