<Tr> <Th> Preceded by </Th> <Td> Irish Famine (1740--41) (Bliain an Áir) </Td> </Tr> <Tr> <Th> Succeeded by </Th> <Td> Irish Famine, 1879 (An Gorta Beag) </Td> </Tr> <P> The Great Famine (Irish: an Gorta Mór, (anɣ ˈgɔɾɣt̪ɣa mɣoːɾɣ)) or the Great Hunger was a period of mass starvation, disease, and emigration in Ireland between 1845 and 1849 . It is sometimes referred to, mostly outside Ireland, as the Irish Potato Famine, because about two - fifths of the population was solely reliant on this cheap crop for a number of historical reasons . During the famine, about one million people died and a million more emigrated from Ireland, causing the island's population to fall by between 20% and 25% . </P> <P> The proximate cause of famine was potato blight, which ravaged potato crops throughout Europe during the 1840s . However, the impact in Ireland was disproportionate, as one third of the population was dependent on the potato for a range of ethnic, religious, political, social, and economic reasons, such as land acquisition, absentee landlords, and the Corn Laws, which all contributed to the disaster to varying degrees and remain the subject of intense historical debate . </P>

When did the irish potato famine officially start