James Ussher was born to a wealthy family in Dublin on 4th January 1581. At age 13 he entered Trinity College and received his Bachelor of arts degree 4 years later and MA 2 years after that. At around 21 he was ordained as deacon of the chapel at Trinity and it is also reported that his uncle ordained him as a priest on the same day, who was at that time the primate of all Ireland. He was nominated to be Archbishop of Armagh and Primate of all Ireland.
Battle Front: Catholic Doctrines
With Charles I offering consessions (or graces) to the catholics of Ireland Ussher prominantly spoke out against the doctrines of the roman catholic church. He held secret meetings with other bishops and published a document against the catholic doctrine.
Battle Front: Arminian Doctrines
The Church of England at this time was growing in arminian doctrines and influence. When pressure came to the Church of Ireland to replace their articles of religion with the English articles, Ussher fought for a rewrite basing them on the English articles but not just replacing them with the English articles.
Battle Front: Civil War
With the 1641 uprising in Ireland Ussher found himself in England where both King and Parliament sought his favour. While parliament gave him a bursary of £400 (he'd lost him home etc in the uprising), the King gave him the property and income of the see of Carlisle.
Surprisingly when civil war broke out in England, the calvinistic Ussher chose not to side with his friends in Parliamnet, but with Charles I. My guess is that like David he would not harm God's annointed. He even asked parliament's permission to leave London and move to royalist held Oxford. That they gave permission shows something of the respect this man had from his peers.
When Cromwell beheaded Charles I, Ussher who was safe to return to London fainted before the axe fell.
After this Ussher devoted himself to research and writing. He'd always been a huge collector of old manuscripts and a lover of Church history. This lead to his most famous book The Annals of the World which followed history (mainly using geneologies) to give a date for creation as being 22nd October 4004 BC. Interestingly he employed an 'agent' to accuire ancient manuscripts from the Middle East. Interestingly his huge library is now in the University of Dublin.
On 19th March 1656 Ussher felt a sharp pain in his side, 2 days later on March 21st at age 75 and with the final prayer of "Oh Lord forgive me, especially for my sins of ommission" Ussher entered the Kingdom of Heaven. Funeral arrangements were made, but Cromwell stepped in and gave this man a State funeral and burial at Westminster Abbey.
That Cromwell honoured his friend, even though he'd taken thr royalis side during the civil war speaks
Yes he would debate and dispute with those of different theology or religions but he seemed to have a gracious mannerism that overshadowed his firey and firm words. He was respected both religiously and politically by those he stood with and those he stood against, and that is not an easy thing to do.