A new online-only exhibition, that includes more than 10,000 items, has been launched to showcase some of the historical treasures of the Oireachtas Library.

Mairéad Treanor, Library and Archive Manager at the House of the Oireachtas, said the archive dates back to the 16th Century and includes historical maps, periodicals, political cartoons, prints and pamphlets.

The collection includes items relating to the 1641 rebellion right up to the turn of the last century.

Ms Treanor told RTÉ: "It essentially was a reference point of British administration in Ireland. We inherited the collection in 1924 from the Dublin Castle Chief Sectretary's Office there and also from the Irish office in London.

"Dating from the 16th Century until the early 20th Century, it reflects the major themes and topics in Irish history over the course of those 300 or 400 years."

Speaking at today's launch, Ceann Comhairle Seán Ó Fearghaíl said the vast collection held in the Oireachtas Library is being made available to as many people as possible at the click of a button as part of the Dáil centenary celebrations.

Mr Ó Fearghaíl said there are a myriad of documents and people with different interests will find different documents interesting. 

He said the one document that stood out for him was "a pamphlet produced in the context of Ireland of 1917 where we were reaching out and looking to the United States for moral and financial support.

"And that juxtaposed with correspondence from America to Ireland in 1775 where the revolutionaries were looking to Ireland and asking Ireland to support them in their efforts".

To add a human interest element to the project, guest curators were invited to look at the treasures in the collection and choose their favourites.

John Lonergan, the former governor of Mountjoy Prison, was one of the guest curators. 

He said: "It is very important to know where we are coming from. We must look back to look forward. I was focusing on the penal system and the reports from the 17th, 18th and 19th Century.

"It is a real eye-opener for legislators because of modern day people advocating tougher times and tougher regimes in prisons. The regimes in those days were horrendous and the reports highlight that."

He singled out a document written by Major James Palmer in the mid 19th Century where he focused on prison reform rather than retribution.

"The whole emphasis in those days was on brutality in humanity and retribution. The consequences were horrific for people in prison and those who worked in prison.

"It is very important for legislators and particularly those legislators who would be advocating going back to the old days. The old days were brutal. The old days were a failure.

"They did also damage so from that perspective it is vital that legislators read and become aware of the past when they are planning the future."

The hidden treasures of the Oireachtas can be explored online at https://www.dail100.ie/en/oireachtas-library