It seems that the German philosopher and political theorist became a little obsessed with Ireland after he met Mary Burns, who was of Irish extraction, in Manchester. He visited Ireland twice during his lifetime and planned to write a history of the country. He even learned Irish to be able to study its history. Sadly, he never managed it, as he died before it could be completed.
Friedrich Engels in 1856. Image source: https://commons.wikimedia.org/wiki/File:Engels_1856.jpg
