Kotelny, Faddeyevsky and Bunge Land are usually named as separate islands on most 20th century maps, although sometimes on the newest maps the name "Kotelny" is applied to the whole island. A flat, low-lying, plain connecting both is known as Bunge Land (Земля Бунге).
The total area of Kotelny Island is 23,165 km². Kotelny is one of the 50 largest islands in the world. These merged islands are a practically uninhabited territory belonging to the Sakha Republic (Yakutia) of the Russian Federation.
The island was officially discovered by a Russian merchant and hunter, Ivan Lyakhov, with the merchant Protod’yakonov, in 1773. In 1770, Ivan Lyakhov noticed reindeer tracks heading seaward across the sea ice. In 1773, he and Protod’yakonov discovered the Lyakhovsky Islands by boat using the bearing of these tracks. Continuing from the Lyakhovsky Islands, they discovered Kotelny Island and named it "Kettle Island" after a copper kettle, which they found while exploring it. The person(s), who visited Kotelny Island and left the copper kettle, is unknown. Formerly this island had been known as "Thaddeus Island" or "Thaddeus Islands" in some maps.
Under the employment of Semen and Lev Syrovatskiy, Yakov Sannikov conducted numerous hunting and cartographic expeditions between 1800 and 1810. On one of these expeditions in 1805, he discovered Faddeyevsky Island. In 1809–1810 Yakov Sannikov and Matvei Gedenschtrom went to the New Siberian Islands on a cartographic expedition. Yakov Sannikov reported the sighting of a "new land" north of Kotelny in 1811. This became the myth of Zemlya Sannikova or "Sannikov Land".
In 1886 Baron Eduard Von Toll thought that he had seen an unknown land north of Kotelny. He guessed that this was the so-called "Zemlya Sannikova".