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UK Economic and Social Research Council

Mapping the Gulag
Russia's prison system from the 1930s to the present

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Data and Methodology

The Russian 'power ministries', of which the Federal Penal Service is one, remain secretive and suspicious of scholars showing an interest in their activities, so there are inevitably severe problems accessing the data needed to map Russia's changing penal geography.

The sources of data used to create the maps on this site are diverse, and our strategy of piecing together a patchwork of data reflects the difficulty of obtaining information about the Soviet and Russian penal systems. We draw upon official data where this is available, data collated by prisoner support groups, and information published by human rights NGOs. The sources of data and the methodologies employed varied between the Soviet and the post-Soviet period.

The Soviet period

We are aware that the actual figures for camp populations are very controversial and have been the subject of intense academic debate. Data for the early Soviet period, specifically 1929-1960, are available courtesy of the non-governmental organisation 'Memorial' which has traced the location of hundreds of penal institutions and collated prisoner numbers for each institution where these exist. No data are publicly available for the period after 1960 to the collapse of the USSR.

In addition to published materials, Russian historians working in central and regional archives have provided data that have allowed us to map the distribution of the gulag at spatial scales below the level of the USSR and Russian republic. Dr Andrei Suslov provided the materials that form the basis of the maps of special settlements in Perm' krai. These data are very rich so that in addition to mapping the distribution of the command centres for special settlements, have allowed us to make maps relating to the principal employments of the 'contingent' in special settlements, the total population of special settlers and to identify clusters of settlements.

We faced a number of challenges in mapping the Memorial data for 1929-1960.

First, we wanted to know where prisoners were and when, but tracing them was problematic. The Gulag was a fluid organisation; institutions, by which we mean prisons, camps, and prisoner settlements, changed both their names and locations over time, for a variety of reasons. Where prisoners actually were was frequently different from the site of the camp 'administration', especially where prisoner labour was mobile rather than sedentary (eg building a railroad). In many cases Memorial has traced the exact location of institutions, and we have used this precise data where it exists. In other cases the raion, the smallest level of regional division, is known, but not the exact location of the institution, and here we have used the raion centre as a proxy.

Second, although prisoner censuses were taken fairly frequently between 1929 and 1960, the same census dates were not used for all institutions. This meant that taking 'snapshots' on specific dates was problematic, and risked vastly underestimating prisoner numbers. We tackled this problem by treating location of institutions and prisoner number as two separate datasets. By using Memorial's prisoner number data we established the 'lifespan' of particular institutions - the periods for which they were operational, and mapped the location of these institutions on 'dot maps', over two-yearly intervals, to show the geographical expansion and contraction of the Gulag.

Using the Memorial archive data, we have produced for each camp a 1-year average number of prisoners. If for example, there were figures for a particular camp every year for a five year period, we would sum and divide by 5. If there was only one year's population, we would take that one. If there were two years, we would sum and divide by 2. We would then sum the average for each camp that we had to achiev an approximate overall total. This is very approximate - we are deriving a hypothetical average, because it does not relate accurately to any particular year. The year groups have been chosen in order to make sure that we have some prisoner population figures for every camp in the USSR.

Finally, since Memorial's data is for the entire Soviet Union, we have mapped the Gulag in its entirety. However, we have also generated a series of maps of the Russian Soviet Socialist Republic, precursor to the Russian Federation, in order to facilitate comparison with our contemporary maps from the period post-1991.

The post-Soviet period

No data source comparable to Memorial's exists for the period after 1991. The Russian government of course holds information about prisoner numbers, but much of this is withheld from the public domain. The location penal institutions is available on the official prison service website In the last few years the regional penal authorities have developed websites which can contain data relating to the number of prisoners held in specific colonies and remand prisons and/or the capacity of colonies. The maps that we include showing the number of prisoners and rates of imprisonment use these data. We have checked official numbers against informal sources available on the web such as sites developed by prisoners’ relatives and NGOs which also can contain information about the number of prisoners in specific colonies. Necessarily, however, we must caution against placing too much faith in the accuracy of the maps relating to the penal population in series 4.

Just as the Soviet period had specific characteristics, the contemporary Russian penal system has a categorisation of institution types that affects the ways in which it can be mapped.

Russian correctional institutions are divided into different categories:

  • Remand Colonies (SIZO – sledstvennyi isolator) - Institutions for persons awaiting trial.
  • Educational Juvenile Correctional Colonies (VK – vospitatel'naya koloniya) for boys and girls aged 14-18.
  • Correctional Colonies for Adult Offenders (IK – ispravital'naya koloniya) - An IK is a secure isolated institution. Internally the colonies are divided into several zones: work zone, residential zone, punishment, hospital, educational, administrative etc. Men and women are imprisoned in separate IKs. There are three types of IK:
    • General (Obshchii) regime (minimum security) for all men (other than those listed below), and all women
    • Strict (Osobii) regime (medium to maximum security), for first-time male offenders convicted of particularly grave crimes, repeat male offenders, who have previously been sentenced to imprisonment
    • Special (Strogii) regime (maximum security), for men convicted of particularly dangerous repeat crimes, who have been sentenced to life imprisonment
  • Isolation colonies for adults with infectious diseases (LIU – lechebnoe ispravitelnoe uchrezhdenie)
  • Colony-Settlements (KP – koloniya poseleniya) - These are often called 'open prisons'. They are located in or close to civilian settlements, but the majority are in very remote parts of Russia. Prisoners generally live in barracks but work outside of the colony.
  • 'Prisons' - The term 'prison' (tyurma) describes Russia's strictest form of punishment for only 4-5% of Russian prisoners. Residential blocks are more similar to cellular accommodation than barracks, and there are severe restrictions on visiting, communication, and exercise.
  • Hospital Colonies (LPU – lechebnoe profilakticheskoe uchrezhdenie) - For inmates requiring serious medical treatment during incarceration.

As was the case in the Soviet period, whereas prison locations are in the public domain, prisoner numbers are not. In view of this lack of data, we have developed proxies for regional prisoner populations, by calculating the average size of each type of institution using data on maximum prison capacity which is publicly available, and multiplying these by the number of institutions in the region. This approach, whilst the only means to estimate regional prisoner populations in Russia, generates relative rather than absolute data.

We understand that these figures are only approximate but we believe that they accurately represent the relative densities of prisoners in different regions. Please send any comments to