It is named after Earnslaw (formerly Herneslawe) village in the parish of Eccles, Berwickshire, hometown of the surveyor John Turnbull Thomson's father.

In March 1882, with guides Emil Boss and Ulrich Kaufmann, he attempted Earnslaw, but transport and weather problems forced them to turn back after climbing 5,000 feet (1,500 metres).

After several attempts over a period of years, Glenorchy guide Harry Birley climbed the eastern peak of Earnslaw in 1890.

[5] He left a bent shilling in an Irish Moss bottle within a stone cairn, to prove he had reached the top.

The 10 m lower, but much more challenging West Peak, 2.5 km to the west-south-west and separated by a 200 m deep pass, was climbed in 1914 by H.F. Wright and J.