The fish eagles, booted eagles, and harpy eagles have traditionally been placed in the subfamily Buteoninae together with the buzzard-hawks (buteonine hawks) and harriers. Some authors may treat these groups as tribes of the Buteoninae. Lerner & Mindell proposed separating the eagle groups into their own subfamilies of Accipitridae.
Sea eagles or fish eagles take fish as a large part of their diets, either fresh or as carrion.
Proposed subfamily Haliaeetinae. Genera: Haliaeetus, Ichthyophaga.
Some authors include Gypohierax angolensis, the “vulturine fish eagle” (also called the palm-nut vulture) in this group. However, genetic analyses indicate it is related to a grouping of Neophron–Gypaetus–Eutriorchis (Egyptian vulture, bearded vulture (lammergeier), and Madagascan serpent eagle).
The fish eagles have a close genetic relationship with Haliastur and Milvus; the whole group is only distantly related to the Buteo group.