When he started out, he was lacking alliances and without a glorious rule. Out of fear of being overrun by another leader, he decided to go on conquests himself to do others, what he was afraid they would do to him. He didn’t finish dominating other kingdoms until he had been to all the ones around him. Much like Alexander The Great, he did not wish to establish his own rule in the kingdoms he dominated, he merely wanted them to understand that they answered to him and wanted them to pay him yearly tributes; most likely of gold or other valuable riches.

Welkin is an archaic term referring to the heavens.

This passage also includes one of the poem’s interesting kennings. A kenning is a word that employs figurative language in place of a single noun. Kennings are strongly associated with Old Norse and Old English poetry. For this passage, “Till all his neighbors o'er sea were compelled to/ Bow to his bidding…”–the Old English is “oð þæt him aéghwylc þára ymbsittendra/ ofer hronráde hýran scolde.” The word ‘sea’ in this instance is “hronrade” or “whale-road.” In other words, to spice up the poem’s language, the poet uses “whale-road” as a description of the sea rather than just using the noun “sea.” Beowulf is full of these kennings, and it’s one of the reasons that the poem remains so fascinating to scholars.