President Michael D Higgins has called for a renewed commitment to support all those who suffer now like Irish people did during the Great Famine.
Addressing today's annual National Famine Commemoration in Cork, President Higgins said given the "catastrophic dimension" of Ireland's history, "we must deliver not only charity but justice".
President Higgins said the 21st Century will be defined by three great global challenges: climate change, the urgent need to help refugees, and sustainable development.
He said Irish people - given their own catastrophic history – cannot be indifferent to the needs of others.
He said fulfilling commitments of the Sustainable Development Goals and the Paris Climate Accord will be a struggle but it cannot be "met with such an indifference as would mean simply abandoning and jettisoning millions of our fellow human beings".
He described the Great Famine as the single most important event in the history of this country, giving rise to a "distinctive form of Irish modernity", and which brought out the "very best and worst instincts of humanity".
He said the Famine was also the single most important event in the formation of a distinct Irish-American cultural identity", a bond that is still "treasured today".
President Higgins praised University College Cork for being to the fore of scholarship of the period, citing the impact of the Atlas of the Great Irish Famine.
He also referred to the impact of the Great Famine on the decline in the Irish language.
Up to four million people spoke Irish, in courtrooms, churches, and in political life in the 1830s - by 1851, the Census records only 1.5 million Irish speakers.
President Higgins was joined by Ambassadors to Ireland from 52 countries at the Commemoration this afternoon.
Also in attendance are members of the Diplomatic Corps, the Lord Mayor of Cork, Councillor Tony Fitzgerald, the Mayor of County Cork, Councillor Declan Hurley, and the Presidents of both UCC and CIT.
The commemoration pays tribute to those who died or suffered in the Famine and will involve music performances, words of remembrance, military honours and the wreath-laying ceremonies.
It is estimated that a million people died during the Famine and another million emigrated.
A replica mud cabin - An Bothán - to serve as a stark reminder of how the poorest live, and died, during the Great Irish Famine of 1845 to 1852 has been recreated near the Quad in UCC, as part of the commemoration.
Built by the buildings and estates staff at the College, it will remain in place over the coming months.
Mike Murphy, head of Cartography in UCC's Geography Department said as many as two million people were living in these mud cabins in 1841 - and the majority of the misery associated with the Famine occurred in them.
A new online resource, the Great Famine Online was also officially launched by Tánaiste Simon Coveney.
Born out of the Atlas of the Great Famine, it marks a major collaboration between UCC's Geography Department and the Department of Culture, Heritage & the Gaeltacht.
The online resource will allow users find out how the famine affected the area where they lived.
Two new pieces of music have been specially commissioned from composer Seán Doherty - one is Professor Boole's Farewell based on the description of Ireland when he arrived in Cork in 1849, and the second piece of music is called Fr McCarthy's Lament 1847 based on a letter depicting terrible times in his parish of Watergrasshill.
A number of other events were due to take place over the weekend, including the laying of wreaths at St. Joseph's Cemetery in Ballyphehane, and at the All Saints Cemetry on Carr's Hill.
Over 40,000 people who died in the Famine are interred in both cemeteries.
UCC marking National Famine Commemoration