Board Thread:General Discussion/@comment-206.74.175.104-20151018163917/@comment-26893431-20160206190310

Draevan13 wrote: Their navy couldn't have held the entire coastline of the Isles forever. Eventually Imperial ships would have landed, and once the Altmer ports start falling their ships won't be able to be repaired, and will thus eventually fall into disrepair, while the untouched Imperial ports can keep pumping out fresh ships in perpetuity. In a war of attrition the Altmer couldn't hold out against all of Tamriel forever. On the occasions when the Elves probe the Empire's defenses, the Legions have sent them back in tatters. Indeed, the Colovians have taken to calling their enemy the "Old Mary" Dominion, for the womanly offensives of its Elven soldiers. The situation at sea, however, is another story, and the Dominion terrorizes the southern waters from the  Cape of the Blue Divide  to the  Topal Bay. -Pocket Guide to the Empire, first edition: Aldmeri Dominion

If you know anything about the maps of Tamriel, this is more than enough evidence to show that Tiber didn't stand a chance.