This is a preliminary essay, outlining some important facts about Thallus, a pagan chronologer of unknown date who is occasionally mentioned in the works of Christian apologists, modern and ancient, as a 1st century pagan witness to the gospel tradition of a “darkness” at the death of Christ: see Mark 15:33; Luke 23:44; and Matthew 27:51-53, whose account includes an earthquake, split rocks, and zombies; John makes no mention of any such events, nor does Paul or any other New Testament author.
Such a story has obvious mythic overtones and can easily be doubted. That a solar eclipse should mark the death of a king was common lore among Greeks and other Mediterranean peoples (Herodotus 7.37, Plutarch Pelopidas 31.3 and Aemilius Paulus 17.7-11, Dio Cassius 55.29.3, John Lydus De Ostentis 70.a), and that such events corresponded with earthquakes was also a scientific superstition (Aristotle Meteorology 367.b.2, Pliny Natural History 2.195, Virgil Georgics 2.47.478-80). It was also typical to assimilate eclipses to major historic events, even when they did not originally correspond, or to invent eclipses for this purpose (Préaux claims to have counted 200 examples in extant literature; Boeuffle and Newton have also remarked on this tendency). The gospel stories also make a solar eclipse impossible: the crucifixion passover happened during a full moon, and the darkness supposedly lasted three hours (indeed, Julius Africanus claimed it covered the whole world). Such an impossible event would not fail to be recorded in the works of Seneca, Pliny, Josephus or other historians, yet it is not mentioned anywhere else outside of Christian rhetoric, so we can probably dismiss the idea of this being a real event.