Boromir, son of Denethor II (last Steward of Gondor) was born near the end (year 2978) of the Third Age. A valiant warrior, and bold leader, he lived in a heavy time for Gondor. Sauron's power was increasing in the east, and Boromir's people looked ever more towards the north for aid. It was when this need was greated that Boromir shared a dream with his brother, Faramir. The dream filled him with fear and hope, and is here reproduced:
Seek for the Sword that was broken:
In Imladris it dwells;
There shall be counsels taken
Stronger than Morgul-spells.
There shall be shown a token
That Doom is near at hand,
For Isildur's Bane shall waken,
And the Halfling forth shall stand.
Boromir was burdened with the fate of his people. He felt it was his responsibility to save them, and this fire could overpower his wits, or simply make him more earnest. After the coming of the dream, Boromir left his people to seek the counsel of Elrond. For 110 days he journeyed, and found the Last Homely House around the time Frodo came there.

In Rivendell, Boromir joined the Company of the Ring and ventured south with them, holding a secret longing to take the Ring to his father and throw down the Dark Lord. It wasn't until the party had reached Amon Hen that Boromir's desire overtook him, and he attacked Frodo Baggins. Panicking, Frodo escaped and departed with Sam Gamgee to complete the quest alone.

By the time Boromir fully realised his folly, it was too late. The party had split up looking for Frodo when Merry and Pippin were attacked by orcs. Bounding through the forest, he defended the hobbits in vain, one man against countless droves. A mile away, Aragorn heard the battle cries, and ran towards the sound of Boromir's horn. It was too late.
He was sitting with his back to a great tree, as if he was resting. But Aragorn saw that he was pierced with many black-feathered arrows; his sword was still in his hand, but it was broken near the hilt; his horn cloven in two was at his side. Many Orcs lay slain, piled up all about him and at his feet.

Aragorn knelt beside him. Boromir opened his eyes and strove to speak. At last slow words came. "I tried to take the Ring from Frodo," he said. "I am sorry. I have paid." His glance strayed to his fallen enemies; twenty at least lay there. "They have gone, the Halflings, the Orcs have taken them. I think they are not dead. Orcs bound them." He paused and his eyes closed wearily. After a moment he spoke again.

"Farewell, Aragorn! Go to Minas Tirith and save my people! I have failed."
Those were his last words, and many were the lamentations of Gondor. Aragorn, Legolas, and Gimli built a funeral boat and placed Boromir upon it. His belongings were put on and around him, and the swords of the slain orcs were at his feet. He drifted down the Anduin, and some believe the boat survived the waterfalls, floating into the Great Sea.

J.R.R. Tolkien Node