Jèrriais was not an official legislative or administrative language for most of its history; it was officially adopted as an official language of the States Assembly alongside English and French only recently, in 2019
What, exactly, makes Jersey Jersey? Some had said Jerriais. But it is surely not just language. If you look at the broad sweep of history, distinctively Jersey aspects have changed over the centuries. Some things have vanished completely. Pre-Norman Jersey probably was more aligned to Breton, and had the Brythonic language.
Before the 933 AD annexation of the Channel Islands by William Longsword, Duke of Normandy, Jersey’s linguistic landscape was a complex, evolving layer of Celtic, Roman, and Germanic influences.
During the 9th century, the Channel Islands fell explicitly under the political sphere and hegemony of the Kingdom of Brittany under leaders like Erispoe and Salomon. The Brythonic language and the Latin names of the Islands (the Antonine Maritime Itinerary) was lost. St Brelade is one of the few legacy saints of the Celtic times.
What truly sets the island apart is that because it is a tidal island. So Jèrriais didn't just differ from the mainland Normandy, it fractured into micro-dialects from parish to parish. Historically, a speaker from the western parish of St. Ouen pronounced vowels entirely differently, used different vocabulary, and could be immediately distinguished from a speaker living just a few miles east in Faldouet or St. Martin.
But the decline means that just one dialect is taught. The modern revival of Jèrriais has been intentionally standardized around the St Ouen dialect. The distinct phonetic markers of eastern parishes like St Martin or Trinity have mostly faded from active daily speech as the last generation of those native speakers passes away.
The 12th-century Jersey-born poet Wace wrote in Anglo-Norman/Old Norman (Roman de Brut, Roman de Rou). While this represents the historical root of the Romance dialect family on the island, Wace's medieval Norman is linguistically distant from modern spoken Jèrriais. To say he was the first person to write in Jerriais is really to stretch historical credibility too far.
Before the 1780s, Jèrriais was purely an oral tongue. If islanders wrote, they used standard "lé bouôn français" (good French) for legal documents, court proceedings, and church services. By the mid-1800s, Jèrriais writing shifted from casual newspaper columns into serious literature. Inspired by the global success of Robert Burns writing in local Scots, Jersey writers decided to deliberately preserve their spoken tongue in print.
The written system used today is entirely modern and completely different from Wace’s medieval text. The script, orthography, and visual style of modern Jèrriais were forged in the 19th and 20th centuries to capture sounds that Wace never would have recognized.
When 19th-century writers began writing Jèrriais down systematically, they didn't have an unbroken spelling tradition dating back to the Middle Ages. They had to invent an orthography on the spot, using Standard French spelling as their anchor. Because Jèrriais contains sounds that do not exist in Standard French, they had to invent completely new visual system
So to focus alone on Jerriais as distinctly Jersey is I think flawed: (a) it was not the main language until after Norman annexation (b) Jerriais comes from roots in the Norman French of the time (as with Wace) but modern Jerriais is linguistically very different because it evolved since then (c) it has many dialects and what we have now is just one variation (d) the modern written form dates mainly from the 18th century, not exactly ancient!
I'm not saying it is not worth keeping in some form or other, but I do want to dispel the idea that we are preserving something very ancient which had not changed.