This is a great series, no doubt about it. It's long (seven novels plus graphic novel prequel) but it's worth it. There is a bit of everything here for the science fiction/space opera fan.
Prequel: Veiled Alliances
This graphic novel is a prequel to the main series novels. Eleven exploratory ships carrying people who don't want their descendants to have to live on what they see Earth becoming have now been discovered by another, more advanced, space-faring civilization, the Ildaran Empire. The empire helps the refugees — by now the several-generations-later offspring of the original voyagers — settle in suitable situations and sends diplomats with a few of them to Earth to establish commerce and other connections. Meanwhile, both Earth and Ildaran authorities bring hidden agendas to their first-contact discussions. The book stands out for its superlative art by Robert Teranishi, whose rendering of characters, machines and alien planets is stunning.
Book #1: Hidden Empire
Having colonized the worlds of the Spiral Arm, the three branches of humanity -- the Earth-based Terran Hanseatic League, the telepathic green priests of Theroc, and the fiercely rebellious, starship-dwelling Roamers - consider themselves lords of creation. After all, humans share the galaxy with only two alien species, one harmless and one extinct. The benign Ildirans are an ancient, senescent civilization, while the Klikiss vanished ages before, leaving behind vast ruins filled with technological wonders, but no clues to their mysterious disappearance.
Book #2: A Forest of Stars
Five years after attacking human-colonized worlds of the Spiral Arm, the enigmatic hydrogues maintain absolute control over the galaxy's gas giant planets. On Earth, the corrupt government is exploiting the crisis, tightening an iron grip on rebellious colonies while seeking to dominate the other humans throughout the galaxy. Earth's alien "friends," the seemingly gentle Ildirans, are secretly abducting and breeding people in enforced sex camps. And the government is using military robots to build cybernetic legions to fight the war, robots that have exterminated their own makers and may turn on mankind.
Book #3: Horizon Storms
The titanic war between hydrogues - powerful aliens that live within gas-giant planets - and faeros, fiery creatures inhabiting suns, continues to sweep across the Spiral Arm, extinguishing suns and destroying planets. It is a time when Chairman Basil Wenceslas of the Terran Hanseatic League and his figurehead King Peter must unify all branches of the human race to stand together against the threat . . . even if they must resort to deception and oppression to do so.
Book #4: Scattered Suns
The destructive hydrogues continue their war against humans and the fiery entities, the faeros - a struggle that kills planets and extinguishes whole stars. Newly crowned Mage-Imperator Jora'h, the leader of the ancient and vast Ildiran Empire, struggles with new knowledge he has learned: an ancient bargain and long-standing treachery that may finally bring peace with the hydrogues . . . though it could mean the extermination of the human race.
Book #5: Of Fire and Night
The extermination of mankind is at hand. In a war against alien races, killer robots, and elemental beings, Earth slips deeper into desperation. The Terran government always knew the hydrogues were a vicious enemy bent on humanity's destruction, but they didn't predict how many other factions would turn against them.
Book #6: Metal Swarm
The alien hydrogues have been defeated, driven back into the cores of their gas-giant planets by an alliance of the Earth Defence Forces, the ancient Ildiran Empire, the gypsy-like Roamer clans and fantasic water elemental beings as well as gigantic living 'treeships'. But as the various factions try to pick up the pieces and recover, the deep-seated wounds may be fatal.
Book #7: The Ashes of Worlds
The culminating volume in Kevin J. Anderson's Saga of Seven Suns weaves together the myriad storylines into a spectacular grand finale. Galactic empires clash, elemental beings devastate whole planetary systems, and the factions of humanity are pitted against each other. Heroes rise and enemies make their last stands in the climax of an epic tale seven years in the making. The Saga of Seven Suns is one of the most colorful and spectacular science fiction epics of the last decade.