The Eagle's Prey has 480 pages.
Under the Eagle has 256 pages.
The Eagle Has Flown has 352 pages.
The Eagle's Conquest has 256 pages.
A Catskill Eagle has 311 pages.
The Eagle of the Ninth has 255 pages.
"The Eagle Has Landed" by Jack Higgins typically has around 400-500 pages, depending on the edition and formatting.
378
Where Once We Walked has 736 pages.
Once - novel - has 150 pages.
Once Upon an Island has 224 pages.
Once a Hero - novel - has 400 pages.