Tsavong Lah is the Yuuzhan Vong Warmaster for most of the invasion, introduced in Michael A. Stackpole's Dark Tide II: Ruin (Del Rey, 2000) as the commander manoeuvring behind Shedao Shai and rising to overall command thereafter.
His defining act is political rather than military. Lah issues an ultimatum to the New Republic: surrender the Jedi, and the invasion will stop. It is a lie, and it works anyway — worlds turn on their own Jedi, mobs form, and the Republic spends a book and a half discovering that its unity was contingent. It is the single most effective thing anyone does to the New Republic in nineteen novels, and it costs the Yuuzhan Vong nothing.
He is mortally wounded by Jacen Solo at Duro and finally dies fighting Jaina Solo at Ebaq 9, which is where the series' long, deliberate construction of Jaina as the Sword of the Jedi pays out.
