Although there has been some discussion over the years as to the meaning of the last line of the poem, the most common interpretation is that the eagle does indeed die, a victim of old age and infirmity.  The reason for the more popular acceptance of this interpretation over one which would have the eagle plummeting purposefully down to earth before soaring once again in the sky is because of the themes Tennyson brings out in the rest of the poem.  Although the author paints a portrait of the eagle as majestic and strong, standing high above "the azure world", in line 2 he makes an allusion to the myth of Icarus, who after getting too close to the sun, falls to the earth and dies.  He also speaks of "walls", a symbol of limitations.  It is most commonly understood that by having the eagle fall unintentionally from the mountain...