In this excerpt from beowulf, what do the underlined words imply about shield sheafson?

so. the spear-danes in days gone by
and the kings who ruled them had courage and greatness.

. .

there was shield sheafson, scourge of many tribes,

a wrecker of mead-benches, rampaging among foes.

. .

a foundling to start with, he would flourish later on

. .

in the end each clan on the outlying coasts
beyond the whale-road had to yield to him
and begin to pay tribute. that was one good king.