It may not surprise you that the most common surname in Britain is Smith (as it is in Australia and the US), nor will it come as news that this name is derived from the word for 'blacksmith'.
Smith is what is known as an occupational surname such as Fletcher, Farmer of Thatcher that have their roots in particular trades.
Variants of it are also widespread across Europe, as this map from Marcin Ciura shows.
Marcin, a 40-year-old software engineer from Krakow, told us he made the map after realising the most common English and Polish surnames are derived from the same profession.
Surnames derived from the word 'smith' are the most common in a range of countries on the continent, including France, Portugal, Italy and Russia.
In northern European countries, surnames derived from the word for 'miller' are the most prevalent, while there are clusters for 'landowner' and 'priest' in central and eastern Europe respectively.
The most common occupational surname in Ireland meanwhile? It is derived from the word for 'sea-warrior'. Classic Ireland.
Please note: Kowalski or Ferrari do not directly translate as 'Smith', they are just derived from the same profession.