The Steppe Eagle is very similar to the Tawny Eagle which is smaller and lighter coloured.
The gape of the Steppe Eagle is an easy way to distinguish it from the Tawny Eagle.
The gape of the Steppe Eagle extends beyond the centre of the eye (clearly shown on the 1st, 2nd and last photo) whereas the gape of the Tawny Eagle extends back only to the level of the front of the eye.
The oval nostril (clearly shown on the 1st and 2nd photo) sets it apart from the spotted eagles.

First 4 photos: Serengeti National Park, Tanzania, 12 January 2008
Last photo: Tarangire National Park, Tanzania, 15 January 2008