The Great Potato Famine was devastating to Ireland in the mid-1800s and resulted in one million deaths. Scientists new that a potato blight was to blame for the mass starvation, but the precise strain of the pathogen that triggered it was unknown until fairly recently. "We have finally discovered the identity of the exact strain that caused all this havoc," study co-author Hernán Burbano said. The study named the deadly strain HERB-1 and its discovery was the work of 11 historic samples of potato leaves that were collected about 150 years ago throughout Europe and North America. It's believed that HERB-1 didn't originate in Ireland, but emerged out of Mexico before arriving in European ports.