Strabo Geography 4.5.4

[4] There are also other small islands around Britain; but one, of great extent, Ierna, ¹ lying parallel to it towards the north, long, or rather, wide; concerning which we have nothing certain to relate, further than that its inhabitants are more savage than the Britons, feeding on human flesh, and enormous eaters, and deeming it commendable to devour their deceased fathers, ² as well as openly ³ to have commerce not only with other women, but also with their own mothers and sisters. ⁴ But this we relate perhaps without very competent authority; although to eat human flesh is said to be a Scythian custom; and during the severities of a siege, even the Kelts, the Iberians, and many others, are reported to have done the like. ⁵