Delos > (The smallest of the Cyclades, a floating island till Jupiter chained it to the sea-bed so that Latona, pregnant with Apollo and Diana, might have a secure resting-place for the birth: see Met. 6.157-381) whilom > in ancient times

2 Amid the Aegean Sea long time did stray, 3 Nor made for shipping any certain port,

certain > fixed

4 Till Latona, travelling that way

Latona > (Mother of Apollo and Diana, fathered by Jupiter, and thus persecuted by Juno)

5 (Flying from Juno's wrath and hard assay),

Flying > Fleeing Juno > (Wife and sister of Jupiter) assay > trials; assaults

6 Of her fair twins was there delivered, 7 Which afterwards did rule the night and day;

night and day > (Diana is goddess of the moon and Apollo god of the sun)

8 Thenceforth it firmly was established,