During World War I, Austrohungarian authorities ran a so-called internment camp in Thalerhof (close to Graz in modern Austria). According to Encyclopedia of Ukraine
The first 2,000 prisoners at Thalerhof, the largest camp, arrived on 4 September 1914, and by late 1914 the camp held 8,000 prisoners, 5,700 of them Ukrainians. In November 1916 it had 2,717 prisoners; 85 percent were Ukrainian, 76 percent were peasants, and 7 percent were Greek Catholic priests. Between 1914 and 1916, 14,000 internees passed through the camp. Its strict regime, the authorities' arbitrary actions, the starvation rations, the extremely unsanitary conditions, and various outbreaks of typhus and other diseases resulted in a high mortality rate among the prisoners. Although 1,767 deaths were registered, it can be assumed that there were many more; between 17 January and 31 March 1915 alone, 524 people died.
Were there institutions with similar levels of mortality in Europe prior to Thalerhof? In other words, can Thalerhof be considered the first concentration camp in Europe (putting aside the harmless sounding "internment camp" name)?
If not, what was the first concentration camp in Europe?
Results of my research: There were concentration camps run by the British at the beginning of the 20th century:
A few years later during the Boer War, in what is modern South Africa, Britain's General Kitchener used "concentration camps" to contain hostile civilians. These were mainly Boers, whites of Dutch origin. Blacks were also subjected to this treatment. Some 28,000 whites and 14,000 blacks died in Kitchener's camps. The tactic played a major part in winning the war for the empire.
The article does not say whether or not those concentration camps were located in Britain or South Africa.
Prior to that, there were concentration camps in Cuba, invented by the Spanish general Weyler.
There is a question about concentration camps in general, but it does not mention any European, pre 1930-s concentration camps.
Update 1: My definition of concentration camp:
An institution where civilians (no prisoners of war) are involuntarily kept under conditions that lead to a significantly higher mortality rate than outside that institution in that region.
By this definition, if
- the mortality rate of Thalerhof inmates was significantly higher than the average mortality in Western Ukraine in 1914 and
- its inmates were put their against their will (i. e. would not go there if they had the choice),
then Thalerhof is a concentration camp.