The proximate cause of the Irish Great Famine was the fungal disease Phytophthora infestans, known at the time as 'blight'. Transported from the US where it had been present in previous seasons, the blight 1st appeared in Belgium in June 1845 and spread from there across Northern & Central Europe. It was 1st observed in Ireland on August 20 of that year by Dr.Moore of the Botanic Gardens in Dublin's Glasnevin.