This is not so much 'Christian History', but a really interesting Historical read :)

The Forgotten Archbishop
by Larry Pierce

Updated on 4 April 2005 by request of author.

When it comes to suggesting a date for the creation of the Earth, perhaps few people have been the butt of more ridicule on the subject from sceptics than Archbishop James Ussher. It was Ussher who in the 1650s put forward the idea that this occurred on October 23, 4004 BC, and this year appeared as a marginal note in many Bibles up until about the mid-20th century. So was Ussher a wise man, a charlatan, or just naive? And what should we think about his date?

The Scholar of Honour and Repute
James Ussher was born in Dublin, Ireland, in 1581. As a young man he resolved to devote himself wholly to the work of the Church, and the Lord honoured him in his resolve. At 18 he entered Dublin University, which was then one of the major universities. At 20 he was ordained a deacon and priest in the Anglican Church at Dublin. At 26 he was appointed chairman of the Department of Divinity at Dublin, an honour accorded to very few who were that young. He was a professor from 1607 to 1621, and was twice appointed vice-chancellor of Trinity College, Dublin.

From his early school days he excelled in history, and from the time he was 20 for the next two decades he read every history book he could get his hands on. He excelled in church history and prepared several large authoritative works dealing with the Irish and English churches from the times of the Apostles.

In 1625, he was appointed Archbishop of Armagh, which was the highest position in the Irish Anglican Church. An expert in Semitic languages, he argued for the reliability of the Hebrew text of the Old Testament and wrote widely on Christianity in Asia, and other Bible-related topics.

In 1628, King James appointed him to his Privy Council in Ireland. He was critical of the rebellion against Charles the first. However, Cromwell, who headed the rebellion, held him in great esteem. When Ussher died, Cromwell held a magnificent funeral for him and had him buried in Westminster Abbey.

The Only Reliable Source Document
One of Ussher’s many projects was the writing, in Latin, of a complete history of the world covering every major event from the time of creation to 70 AD. He published this 1600-page tome in Latin in 1650. An English translation was published in 1658, two years after his death. This work is fascinating to read; however, few of us have access to it. The work has been republished and is now available in the Answers in Genesis bookstore. The contents of the first volume of his work are also available online. It covers the period from creation to 176 BC.

In preparing this work, Ussher first made the assumption that the Bible was the only reliable source document of chronological information for the time periods covered in the Bible. In fact, before the Persian Empire, very little is known about Greek, Roman, and Egyptian history, or the history of other nations. Much rests on speculation and myths. Dates in secular history become more certain with the founding of the Media-Persian Empire.

For events before this time, Ussher relied solely on the data from the Bible to erect his historical framework. He chose the death of Nebuchadnezzar as a reliable date to anchor all the earlier biblical dates to. Hence, working backward from that date, he ended up with his date for creation of October 23, 4004 BC.

How Did He Arrive At This Date?
Nowhere in your Bible does it say that the day was October 23. Because the Jews and many other ancient peoples started their year in the autumn, Ussher assumed there must be a good reason for it. He therefore concluded that God created the world in the autumn. After consulting astronomical tables he picked the first Sunday after the autumnal equinox.

We all know that the equinox occurs around September 21, not October 23. Well, it does now, thanks to some juggling of the calendar. In his studies, Ussher found that the ancient Jews and the Egyptians did not use a year based on the moon. Instead they had a year made up of twelve months, each thirty days long. At the end of the year they tacked on five days. Every four years they added six days. However, a year of 365 days is too short, and one of exactly 365.25 days is too long. You have to drop days from it to keep the seasons from drifting.

When Julius Caesar reformed the calendar, he adopted the system we now use, with twelve months of various lengths. On September 2, 1752, eleven days were dropped from the English calendar to make the seasons start when they were supposed to. Another day was dropped in 1800 and again in 1900. These years would normally have been leap years, but were made normal years to keep the calendar in line. Today we use the Gregorian calendar which is a refinement of the Julian calendar.

Before Julius Caesar’s reform, no correcting adjustments were made to the calendar. For the four thousand years from Caesar’s time to the time of creation almost thirty-two days have to be dropped to make the seasons start when they should. Hence, by making these adjustments, Ussher arrived at the date of October 23, not September 21.

Now you ask, how did he get the year 4004 BC?

Answer: He took the chronologies in Genesis 5 and 11, together with some other Bible passages which we will look at. To simplify the calculations, we will tie the chronology to the fall of Jerusalem in 588 BC. The detailed calculations cover over 100 pages in the original document!

From Genesis 5 we get the following:

First Genealogy-Genesis 5
Verse Event Age of the Earth
1:1-31 Creation 0
5:3 Seth born when Adam, 130 130
5:6 Enos born when Seth, 105 235
5:9 Cainan born when Enos, 90 325
5:12 Mahalaleel born when Cainan, 70 395
5:15 Jared born when Mahalaleel, 65 460
5:18 Enoch born when Jared, 162 622
5:21 Methuselah born when Enoch, 65 687
5:25 Lamech born when Methuselah, 187 874
5:28 Noah born when Lamech, 182 1056
11:10 Shem born when Noah, 502 1558
7:6 Flood when Noah, 600 1656

From Genesis 11 we get:

11:10 Arphaxad born when Shem, 100 1658
11:12 Salah born when Arphad, 35 1693
11:14 Eber born when Salah, 30 1723
11:16 Peleg born when Eber, 34 1757
11:18 Reu born when Peleg, 30 1787
11:20 Serug born when Reu, 32 1819
11:22 Nahor born when Serug, 30 1849
11:24 Terah born when Nahor, 29 1878
11:32, 12:4 Abraham born when Terah, 130 2008
12:4 Abraham enters Canaan, 75 2083

In the Bible there are some large time periods given. These enable us to do the same calculations as Ussher, without going into all the intermediate details as he did.

Golden Arches of Time
Abraham left Haran until the Exodus exactly 430 years to the day.
-( Ge 12:10, Ex 12:40, Gal 3:17)
2513
Exodus to start of Temple, 479 years
-( 1 Ki 6:1, in the 480th year or after 479 years)
2992
Start of Temple to division of the Kingdom, 37
-( Solomon reigned 40 years, 1Ki 11:42, temple started in his 4th year)
3029
Division of the Kingdom to final deportation about four years after Jerusalem fell,
390 whole years plus part of one year
(Eze 4:4-6)
Final deportation in 584 BC
3421

Hence date creation = 584 + 3421-1 = 4004 BC

Now you have a rough idea of how Ussher did his calculations.

Ussher started from the Bible and not from secular history. That is why he used a date of 588 BC for the fall of Jerusalem and not 586 BC. He noted that the fourth year of King Jehoiakim’s reign corresponded to the first year of Nebuchadnezzar’s reign. (Jeremiah 25:1) In working through the king lists of Judah, he determined that this was in 607 BC, two years before the death of Nebuchadnezzar’s father. His father died in 605 BC and many historians concluded that this was the start of Nebuchadnezzar’s reign when in fact he was already ruling as viceroy for two years. It was the normal procedure to count as the first year of the reign of a king from the year he became a viceroy. Starting from the Bible, Ussher was able to correct this error in secular history.

So was Ussher Right?
Ussher was neither charlatan nor naive; in fact, he was one of the most learned men of his day. Understanding the assumptions with which he began his calculations (particularly the one we should all begin with, namely that God’s Word is true and reliable), we can readily understand how he arrived at his date for creation. In fact, if one assumes that there are no deliberate ‘jumps’ or gaps in the later genealogies (for which the evidence in my view is inadequate), then his date is a perfectly reasonable deduction based on his detailed knowledge of and reverence for the Word of God.

-taken from http://www.answersingenesis.org/crea...archbishop.asp

I have got the new version of Ushers "Annals of the World", which traces world history from creation to the 1st century. I also have Floyd's chronology, which is published by the same publisher and attempts to vindicate Usher, dealing with many of the problems.
I think they are very useful and interesting recources.

A very interesting read. I am so thrilled when I read or hear, of educated men and woman who followed Jesus.