How did the island of tristan da cunha get its name?

Answer 1

It was discovered by the Portugese explorer Tristao da Cunha in 1506. The islands came into British possession in 1816 and the name was anglicised to Tristan da Cunha
From the explorer who shipwrecked there in the 1500's.

Answer 2

The Island got it's name from the first person on the island, Sir Da cunha.