[@Tangletail]Oh, so it's just coincidence that you happened upon Ba'alzamon's strategy to win the war? Read below:

[hider]The fall of Aridhol was a massive blow to the Westlands, as it allowed the Shadow to now funnel armies into Coremanda and Manetheren. This was the 'hottest' part of the war, with fighting raging throughout those two kingdoms. The armies of Manetheren became famous during this period, with King Thorin and his grandson and successor Aemon achieving great victories over the Shadow with the new tactics. A band of elite warriors grew up around Aemon, the Band of the Red Hand, and their appearance alone on the battlefield could cow the forces of the Shadow. But the Shadow also gained renewed confidence at this time with the emergence of a commander who called himself Ba'alzamon. Rumored to be the Dark One itself at the time, modern historians now prefer the theory that this was the Forsaken Ishamael during one of his periods of liberty from his prison.

Ba'alzamon led the Shadow forces in assaulting Manetheren directly, [u][b]attempting to penetrate into the Manetheren heartland by crossing the River Tarendrelle while the armies of Manetheren were engaged elsewhere[/b][/u]. According to legend, King Aemon al Caar al Thorin marched his army day and night and beat the army of the Shadow [u][b]to a strategically important bridge[/b][/u]. Thus began the Battle of the Tarendrelle River, where the forces of Manetheren held their ground for ten days, awaiting relief forces that had been promised but would never arrive. Eventually, King Aemon's forces were broken and he was forced into a fighting retreat across the heartland of Manetheren ending with a final last stand at the Battle of Aemon's Field where the remaining defenders perished. Eldrene, the king's Aes Sedai wife and queen, felt the severing of their bond the moment he perished. Driven mad with grief, she drew deeply upon the Source and unleashed a vast wave of the One Power that routed the army of Shadowspawn and utterly destroyed the capital of Manetheren.

It was learned later that the then-Amyrlin Seat, Tetsuan, delayed and misdirected reinforcements so they would not arrive in time to save Manetheren. Her actions stemmed from youthful envy of Eldrene, a more powerful channeler. For this crime Tetsuan became the first Amyrlin to be deposed, stripped of staff and stole, and stilled by the Hall of the Tower.

Source: http://wot.wikia.com/wiki/Trolloc_Wars[/hider]

It's discussed in one of the first few chapters of the first book.

EDIT: It's the 9th chapter of The Eye of the World, and Tetsuan's bit is relayed in the 5th chapter of The Great Hunt.

EDIT: "Manetheren blood was always stubborn, and more so after Aemon died and Eldrene's heart was shattered." - Moiraine, The Eye of the World