[3] The genus Haliaeetus was introduced in 1809 by French naturalist Marie Jules César Savigny in his chapter on birds in the Description de l'Égypte.

[8] A 2005 molecular study found that the genus is paraphyletic and subsumes Ichthyophaga, the species diverging into a temperate and tropical group.

A distal left tarsometatarsus (DPC 1652) recovered from early Oligocene deposits of Fayyum, Egypt (Jebel Qatrani Formation, about 33 million years ago (Mya)) is similar in general pattern and some details to that of a modern sea eagle.

[8] The rate of molecular evolution in Haliaeetus is fairly slow, as is to be expected in long-lived birds which take years to successfully reproduce.

[8] The Haliaeetinae subfamily is an especially threatened collection of creatures within the broader Accipitridae species, according to the academic journal Molecular Phylogenetics and Evolution, given the "anthropogenic factors" involved.

The publication reported in 2005 that prior trends had meant that sea eagles could be "found in riverine and coastal habitat[s] throughout the world".