This was a major concern of many Christian scholars over the centuries.
The chronology is sometimes associated with young Earth creationism, which holds that the Universe was created only a few millennia ago by God as described in the first two chapters of the biblical book of Genesis. Published in 1650, the full title of Ussher's work in Latin is Annales Veteris Testamenti, a prima mundi origine deducti, una cum rerum Asiaticarum et Aegyptiacarum chronico, a temporis historici principio usque ad Maccabaicorum initia producto ("Annals of the Old Testament, deduced from the first origins of the world, the chronicle of Asiatic and Egyptian matters together produced from the beginning of historical time up to the beginnings of Maccabees").
Ussher's work was his contribution to the long-running theological debate on the age of the Earth.
The key male players are all linked with genealogies and ages. Although also it’s here that the Catholic and Protestant (King James) Bible timelines differ.
The Masoretic text and the Septuagint both link all the key male players, but the Septuagint gives longer time frames for many of them.
This, however, is a misnomer, as the chronology is based on Ussher's work alone and not that of Lightfoot.
Ussher deduced that the first day of creation fell upon, October 23, 4004 BC, in the proleptic Julian calendar, near the autumnal equinox.The season in which Creation occurred was the subject of considerable theological debate in Ussher's time.Many scholars proposed it had taken place in the spring, the start of the Babylonian, Chaldean and other cultures' chronologies.Establishing the chronologies is complicated by the fact that the Bible was compiled by different authors over several centuries with lengthy chronological gaps, making it difficult to do a simple totaling of Biblical ages and dates.In his article on Ussher's calendar, James Barr has identified three distinct periods that Ussher and others had to tackle: After reckoning the years from creation to the last kings of Judah, Ussher used 2 Kings to establish the length of time from the creation to the accession of Babylonian king Amel-Marduk (also known as Evil-Merodach).The Bible timelines differ because they are based on different original texts (the Masoretic or the Septuagint), because some of the dates are based on dating of secular events that have been recalculated by modern historians and also by a re-reading of the Bible in light of new knowledge.