Archbishop James Ussher, Bishop of Armagh (1581–21 March 1656) was the guy who wrote 'The Annuls of the World'.
Basically this book uses Biblical accounts with classical and Middle Eastern history, with the Jewish calendar systems to trace backward through the generations from Ussher's time to Adam. He brings an age to the Earth & even declares a creation date of October 23, 4004 B.C.
This book has been re-printed in recent years, translated into English from the original Latin, & is a great tool for the creationist.
Although his book is very useful for our time with the creation/evolution controversy, the controversy of his day was quite different. 'Was Irish Christianity before the sixteenth century more Roman Catholic, or more Protestant?'
He prepared a long Discourse on the Religion Anciently Professed by the Irish and British, in which he cited primary text on all the issues between Catholics and Protestants. And argued thatthe answer was Protestant.
Ussher’s overall theology is to be found in his 18 Oxford sermons from 1640.
HT:Scriptorium Daily