Four Thousand Years Ago

As soon as Poul Anderson's time traveling characters arrive in the past, the author's skills as a writer of historical fiction take over. When, in The Corridors Of Time, Malcolm Lockridge realizes that he is now nearly four thousand years in the past, he reflects that:

Pharaoh rules Egypt;
the Cretan sea king plans trade with Babylon;
Mohenjodaro thrives in the Indus valley;
the General Grant tree is a seedling;
the Mediterranean is in the Bronze Age;
northern Europe is neolithic;
the dolmen marking the time corridor was erected only a few generations ago;
its builders moved away because their slash-and-burn agriculture exhausted the soil;
it is eighteen hundred years before Christ and even before Abraham;
the Danes have not yet entered Denmark.

Recently, I quoted a similar passage in which two Time Patrolmen had arrived in 1280 AD so we were told who ruled where etc. We are always supremely confident that Anderson knows both his history and his physics and can switch between them as the needs of each particular story require him to.