<human>:  With regards to the Irish potato famine, when did it start and when did it end?
<bot>: The Irish potato famine started in 1845 and lasted until 1852. The cause of the famine was the failure of the potato crop, which is the main food crop in Ireland. The crop failed due to a disease called potato blight. The blight was caused by a fungus called Phytophthora infestans, which spread rapidly through the potato crop. The potato blight destroyed the potato crop and led to widespread starvation.