Old Irish is the name given to the oldest form of the Irish language which can be more or less fully reconstructed from extant sources. However, itts precursor Primitive Irish — does appear in a specialized written form, using a unique script known as Ogham. It dates from the 6th to the 10th century, when it gives way to Middle Irish. 

Old Irish first appears in the margins of Latin religious manuscripts dating as early as the 6th century. A large number of early Irish literary texts, though recorded in manuscripts of the Middle Irish period such as Lebor na hUidre and the Book of Leinster, are essentially Old Irish in character. Old Irish is the ancestor to Modern Irish, Scots Gaelic and Manx Gaelic, it is most definitely distinct from these. Old Irish possesses much more inflection than its descendants, and also employs drastically different phonetic and grammatical structures. 

Basic consonants in Old Irish are t, p, c (k), d, b, g, th, f, n, m, ng, r, l, and s. These are considered the basic consonants because they are the only ones that can stand independant of any phonetic modification. Verbs stand initially in the sentence (preceded only by some particles and very few adverbs). Most verbs have, in addition to the tenses, voices, and moods named above, two sets of forms: a conjunct form, and an absolute form.

The conjunct form typically consists of a preverb (a sort of verbal clarifier used similarly to the a-, e-, in-, etc. in Latin verbs, though not directly related), followed by a verb stem which bears the bulk of the conjugation. Personal pronouns as direct objects are infixed between the preverb and the verbal stem, along with various other particles that modify the verb's meaning (including the negative) or indicate certain special sentence structures.

A single verb can stand as an entire sentence in Old Irish, in which case emphatic particles such as -sa and -se are affixed to the end of the verb.The absolute form is used when no infixes are necessary, and any other necessary elements are given in another part of the sentence.

Old Irish can be traced in the Rhinns of Galloway from at least the fifth century. The Novantae Celtic tribe in Galloway was based in the Rhins area and were known to the Romans as trading partners. In later times the area became part of numerous kingdoms that ruled in the wider region, including Gododdin, Rheged, Strathclyde and Bernicia. The Gaelicization of the land was complete probably by the eleventh century, although some have suggested a date as early as the beginning of the ninth century. Having been settled from ancient times, the area has a long history, forming part of the western kingdoms that collectively ruled most of western Scotland, Ireland, the Isle of Man and Wales.

The principle settlements among the Rhins are Stranraer at the head of Loch Ryan and the small tourist village of Portpatrick on the west coast, other villages are dotted up and down the peninsula, including Kirkcolm, Leswalt, Lochans, Stoneykirk, Sandhead, Ardwell and Drummore. The Southern Upland Way begins in the Rhins at Portpatrick and winds its way through the area on its long journey east across Scotland to its finish at Cockburnspath in the east. The lands of Cockburnspath were part of the dowry given by James IV of Scotland to Margaret Tudor (daughter of Henry VII of England) on their marriage in 1503. This was known as the Marriage of the Thistle and the Rose. James was killed at the Battle of Flodden, just across the border in Northumberland, in 1513.

The southernmost point of the Rhins is also the southernmost point in Scotland, the Mull of Galloway from the history of the Western Isles. It lies close to the old invasion route from England into Scotland. Cockburnspath was initially known as Kolbrand’s Path. The peninsula is bounded on its west coast by the North Channel and by Loch Ryan and Luce Bay in the east. The natural geography of the Rhins has lead directly to the use of the area for development, with the entire peninsula acting as a huge breakwater from the currents of the North Channel and to a lesser extent the Atlantic.