here, including two titles by Poul Anderson. Let us therefore consider the following sequence:
Anderson, Three Hearts And Three Lions
Anderson, A Midsummer Tempest
- three novels of cross-time travel.
However, the two Anderson titles are fantasies, involving supernatural beings and magic, whereas Conquistador by contrast is science fiction, assuming only:
an infinite series of parallel universes with identical physical laws;
a technological means of travel between them.
Adrienne Rolfe's experience differs from ours in just one respect: in the existence of the Gate and of what lies beyond it. However, what is beyond the Gate is an Earth where history went differently, not where myths are true. Thus, Three Hearts... and ...Tempest are as fantastic to Adrienne as they are to us.
Her literary predecessors also include the group of extra-temporal exiles in HG Wells' Men Like Gods but these characters are hardly major players in the history of sf. One major predecessor of many science fictional space and time explorers is the original Time Traveler, who could well have encountered a sabre-tooth as the New Virginians do at the end of Conquistador. In the Epilogue to The Time Machine, the outer narrator speculates that the Time Traveler has gone to:
the Stone Age;
the Cretaceous Sea;
the Jurassic Age;
the Triassic Age -
- so we can legitimately imagine him among prehistoric animals even though Wells never wrote a sequel.