THE LIFE of JESUS and the EMERGENCE of SCIENTIFIC CHRONOLOGY Back in the Thirteenth Century, Roger Bacon Had Already Committed H

CHAPTER EIGHT

THE LIFE OF JESUS AND THE EMERGENCE OF SCIENTIFIC CHRONOLOGY

Back in the thirteenth century, Roger Bacon had already committed himself to the important idea that a ‘certified’ chronology of ancient history had to rely on eclipses of the sun and the moon as independent and precise markers of historical time. It was not until the sixteenth century, however, that this research programme, which in Bacon’s work had the character of a promissory note, was fully put into prac- tice. An early trace of eclipse-based chronological argumentation, which I have briefly discussed in the previous chapter, can be found in Peter de Rivo’s Tercius tractatus and Paul of Middelburg’s Paulina, where the alleged solar eclipse in the last year of Augustus’s reign was used to date the latter’s death to AD 16 and 17 respectively. Another significant step in the development of eclipse-dating came in Scaliger’s birth year 1540, with the publication of Petrus Apianus’s magnificent Astronomicum Caesareum, a richly illustrated astronomical handbook in honour of the Emperor Charles V, which included rotating paper volvelles by which readers were invited to compute mechanically the movements of the planets, the sun, and the moon. In the 29th chapter of his work, Apianus, who was a professor of mathematics at the Bavarian university of Ingolstadt, set forth a programmatic discus- sion of the chronological errors and contradictions found in historical sources and how mathematical astronomy could help to remedy this evil: Everybody is aware that those who pass down deeds and histories all but fall out of the heavens (as they say) when it comes to enumerating the years, sometimes counted from the world, sometimes from the founda- tion of the City. How much darkness, ignorance, doubt, and confusion is introduced by this error every time it comes to evaluating and understanding a work of history, is there to be judged by the scholars. For it therefore happens that, if they want to remind the Christian reader of some memorable event that either preceded or fell not long after the founding of the City, they cannot give a consistent account. Only knowl- edge of eclipses can amend this great evil and restore it to a better state. 262 chapter eight

For eclipses can make it possible to fix all events to precise years, before Christ no less than after him.1 Apianus went on to demonstrate the possibility of correcting historical tradition by astronomical means with three very prominent examples from ancient history. The capture of Nicias following the second battle of Syracuse, the battle of Gaugamela, and the Roman victory over the Macedonian king Perseus at Pydna had all been preceded by famous lunar eclipses, which Apianus respectively dated to 8 September, 414 BC (Oppolzer no. 1226), 28 June, 326 BC (Oppolzer no. 1360), and 2 September, 172 BC (Oppolzer no. 1590). In each case a com- parison with the years implied by Eusebius’s chronicle revealed trou- bling discrepancies. According to Apianus’s own understanding of the chronicle’s dates, the years indicated by Eusebius were AM 4782 = 417 BC, AM 4871 = 328 BC, and AM 5034 = 165 BC—a seven-year difference in the case of the battle of Pydna, which marked the end of the Antigonid dynasty and the dismantling of the Macedonian king- dom. The obvious conclusion was that the services of the astronomer in establishing a reliable chronology were urgently needed.2 Upon closer inspection, however, Apianus’s technical arguments left much room for improvement. His reliance on the Dionysiac era led him to identify Eusebius’s year AM 5199 = Ol. 194.3, in which the birth of Christ was thought to have occurred, with the year AD 1/2 instead of 2/1 BC. As a result, his interpretation of the dates found in the chronicle was marred by a systematic error. For example, while Apianus believed that Eusebius had assigned the battle of Gaugamela to AM 4871 = Ol. 112.3 = 328 BC, basing himself on the simple sub- traction 5199−4871 = 328, the Olympiad date reveals that Eusebius’s

1 Petrus Apianus, Astronomicum Caesareum, I3v: “Nemo ignorat, rerum, histori- arumque traditores in enumerandis tum mundi, tum urbis conditae annis, tantum non, ut dicitur, coelo ipso excidere. Qui quidem error quantum tenebrarum, ignoran- tiae, dubii, confusionisque, in omnia alia historia iudicanda intelligendaque importet, doctorum esto iudicium. Inde enim sit, ut si cuiuspiam rei, memorabilis saltem, lec- torem christianum commonefaciant, quae urbem conditam, aut praecesserit, aut non ita multo post, subsequuta sit, ipsis constare, nullo modo possint. Quod quidem tam grande malum sola ecleipsium cognitio emendare et in melius vertere potest. Per ecleipses enim omnia certos in annos reduci possunt, Christum praecedentes, non minus, quam sequentes.” 2 Ibid., I3v–K2r. See also Anthony Grafton, “Petrus Apianus Draws up a Calendar,” Journal for the History of Astronomy 42 (2011): 55–72; Grafton, Scaliger, 2:121–22. For Eusebius’s AM dates cited by Apianus, see, e.g., Chronicon divinum plane opus eruditissimorum autorum (Basel, 1529), 57r (Nicias), 59r (Gaugamela), 62v–63r (Per- seus’s reign).