The All Flags Navy (sometimes called the All Flags Fleet or the Lost Fleet ) was Tamriel's instrument of vengeance against the Sload of Thras, who were held responsible for releasing the Thrassian Plague in 1E 2200 which claimed more than half the continent's population. The All Flags Navy was formed under Baron-Admiral Bendu Olo, the Colovian King of Anvil, to deal justice upon them. The Navy was composed of ships and sailors from the Redguards, Bretons, Colovians, elves, and Argonians. It was the largest allied naval force in Tamrielic history. Sometime around 1E 2260, they sailed to Thras, slaughtered all the Sload they could find, and used unknown magic to sink their kingdom into the sea (though Thras would rise again later).
The All Flags Navy sailed through the Abecean Sea and into the Sea of Pearls, the waters surrounding the Thrassian Archipelago. There, they sailed through a fierce storm for two days and were beset by a dense fog. The fog created what seemed like a solid cloud encircling the isle of the Sload. Once there, a magical projection of Baron-Admiral Olo appeared on the decks of the ships and issued orders to sack the largest island and lay siege to its coral tower. Soon after they began their assault, the blue light atop this coral tower began to pulse and bleed energy into the clouded sky. Afterwards, the island began to crack and sink into the ocean. The sinking island created a great whirlpool which sucked in roughly half the fleet. These ships evidently were sucked into Coldharbour, the realm of Molag Bal.
Eras later, the notes taken by members of the All Flags Navy still hold some of the only information available in the realms of men regarding the Sload. Sload hold-outs in Auridon were wiped out by a returning remnant of the Navy after the sinking of Thras. Baron-Admiral Olo's tremendous success with the Navy is said to mark when the Colovian Estates began to overshadow eastern Cyrodiil, which would eventually lead to the War of Righteousness.
- Besides Bendu Olo, the only known official of the Navy was Baron-Captain Olsien Guy Mard, an ancestor of the modern Evermore royal family of Guimard.
- Tsona-Ei was First Mate aboard the All-Flags ship the Golden Era, which was under the command of the Captain who made a deal with Molag Bal in order to enslave those who ended up trapped in Coldharbour.
- The Navy was assembled by the command of an Alessian emperor whose name is not known.
- Orthuna's dialogue in ESO
- Pocket Guide to the Empire, 1st Edition: The Wild Regions — Imperial Geographical Society, 2E 864
- Journal of Tsona-Ei — Tsona-Ei
- The Royal House of King Eamond — Seneschal Derric Andras of Castle Evermore
- A Graveyard of Ships quest in ESO.
- Auridon Explored, Chapter III — Fenlil the Wayfarer
- Pocket Guide to the Empire, 1st Edition: Cyrodiil — Imperial Geographical Society, 2E 864