01 - A Hymn Before Battle
02 - Gust Front
03 - When the Devil Dances
04 - Hells Faire
05 - Eye of the Storm
06 - Watch on the Rhine
07 - Yellow Eyes
08 - The Tuloriad
09 - Cally's War
10 - Sister Time
11 - Honor of the Clan
12 - The Hero (spin-off with Michael Z. Williamson)
"
The first four novels cover the Posleen War in which the Posleen invade Earth. Another novel, Cally's War, takes up the story a few decades later; The Hero is set nearly a thousand years later. Watch on the Rhine takes place immediately after Gust Front and extends until March 2008, with the very last chapter taking place at some unspecified point far after the end of Hell's Faire but prior to the beginning of The Hero."
From
ebookee.org.
I've not read the series myself, but that came from the first page of results after googling "legacy aldenata timeline". If no-one else chimes in, it should really only take you minutes to dig deeper.