What purpose did the use of alliteration and rhyme serve in the ballads from the anglo-saxon era?

The purpose that the use of alliteration and rhyme served in the ballads from the Anglo-Saxon era was to remember the text more easily. At the time, these ballads were often sung, so the singers had to remember them by heart.

The answer is william henry harrison pursued and defeated british forces retreating into canada.

The theory is land mass basically what they said.