 Alexander led the so-called "Lowland" army, in fact that of the north-east and eastern Highlands, against Domhnall of Islay, Lord of the Isles at the bloody and indecisive battle of Harlaw in 1411.Unlike his father, who had been unable to keep the peace in the fractious north-east, Alexander, Walter Bower says, "ruled with acceptance nearly all of the north of the country beyond the Mounth".He achieved this not by using different methods from his father but by his ability to keep his cateran forces in check and to use them to protect his extensive lands when needed; the result was that the lowland areas of Aberdeenshire and Moray were protected.