Alternative etymology: Tintagel

Tintagel is an early medieval settlement, fortress, and natural harbour on the extreme western edge of the known world. Tintagel is often seen as a remote outpost of the Roman Empire, with a role in the important international trade in Cornish tin.

That view is wrong, because Tintagel was once at the very heart of several sea lanes that connected it to the centre of the Roman Empire and beyond. Recent archaeological excavations found countless fragments of amphoras that had contained wine and olive oil.

But what does the name 'Tintagel' mean? The accepted etymology is that it derives from Cornish British, where din means 'fort' and tagell 'neck', 'throat' but in the sense of 'constriction'. Thus the name would mean 'fort on the peninsula' or 'fortress by the neck (of the land)'.

But there's a problem with this etymology, because the Cornish language of the 13th century would have lacked the soft 'g' ('i/j' in its earliest forms).

I was wondering if the etymology of Tintagel could possibly be Punic/Phoenician. As Caitlin Green has written, some place-names in Great Britain might have a Punic origin.

Could the origin of the name Tintagel be related to ‘Y TNT, meaning the ‘Isle (of) Tanit’, the chief goddess of the ancient Phoenician mercantile power of Carthage?

This wouldn't be the first location to be named in honour of the goddess Tanit, because a second Isle of Thanet lies at the most easterly point of Kent, England. While in the past it was separated from the mainland by the 600-metre-wide Wantsum Channel, these days it is no longer an island. Like, that of Tintagel, the etymology of this island is also doubtful and often disputed.

So, we have two places named 'Isle of Tanit', each at the extreme edges of the British Isles, Tintagel in the east and the Isle of Thanet in the west.

Because the treacherous Channel Islands would surely appear on Phoenician maps, Caitlin Green also proposes a logical etymology for Sark and finds the Proto-Semitic root *śrq, ‘redden', 'rise (as of the sun)' or 'east’.  Compare that to Modern Arabic šarq, ‘east’, which would give good sense as Sark is the easternmost island of the Guernsey group of islands. Coast hugging vessels would need to cross the perilous English Channel after sighting Sark. Then an easterly course would lead them to Tintagel.

I imagine that Phoenician captains would mark these points on their maps, rutters or experience as they were the start and the end of their perilous voyage to and from Tintagel.