COW Colonial/Dependency Contiguity, 1816-2002 (v3.0)


Version 3.0 of the Correlates of War Colonial/Dependency Contiguity data identifies all contiguity relationships between states in the international system from 1816 through 2002 through their colonies or dependencies. That is, if two dependencies of two states are contiguous, or if one state is contiguous to a dependency of another, the data set reports a contiguity relationship between the two main states (with appropriate codes identifying the relevant dependent entity/entities). The classification system for contiguous dyads is comprised of five categories, one for land contiguity and four for water contiguity. Land contiguity is defined as the intersection of the homeland territory of states/colonies/dependencies in the dyad, either through a land boundary or a river. Water contiguity is divided into four categories, based on a seperation by water of 12, 24, 150, and 400 miles.


In any papers or publications that utilize this data set, users are asked to give the version number and cite the data set, as follows:

Bibliography Entry: Correlates of War 2 Project. Colonial/Dependency Contiguity Data, 1816-2002. Version 3.0. Online:

Data Set

The files associated with the colonial/dependency contiguity data set can be obtained either individually, or in one ZIP file. The data file is in .csv (comma-delimited) format. In this format, values are separated by commas. The first line of the data file is a header record containing the variable names. The data file has a non-directed format in order to prevent asymmetries from accidentally being introduced into the data set. The data set lists only dyads that are contiguous via colonies/possessions; dyads not listed in the data set are not contiguous in this fashion. So, dyads that are directly contiguous (land or sea within 400 miles) are listed in the direct contiguity data set, and not here. Particular state-state pairs may have several different colonial/dependency relationships listed if one or both states have multiple colonies/dependencies. In these cases, separate dyadic relationships are created for each interaction between states/dependencies that fall within the 400 mile range. Examples to assist in interpreting the data are included within the documentation file.

The zip file (Colonial Contiguity contains three separate data files:

Colonial Contiguity v3.0.csv Data on colonial/dependency contiguity relationships, from 1816-2002.
Colonial Contiguity v3.0.pdf Documentation for the data set.
Entities.pdf List of entities (colonies, dependencies, and possessions) referred to in colonial/dependency contiguity data set.


The variables in the data set are as follows.

Variable Contents
CCode1 COW state number (country code ) for the lower numbered state in the dyad (see system membership data set for identification).
Depend1 Entity number of the colony/possession of CCode1 involved in this relationship, if any (see geopolitical unit data set for identification).
CType Type of contiguity, 1-5.
CCode2 COW state number (country code ) for the higher numbered state in the dyad.
Depend2 Entity number of the colony/possession of CCode2 involved in this relationship, if any.
BegYear Beginning year of this contiguity relationship.
EndYear Final year of this contiguity relationship.
Note Version number of the dataset.


Levels of contiguity (variable "CType") are defined as:

Code Condition
1 Separated by a land or river border
2 Separated by 12 miles of water or less
3 Separated by 24 miles of water or less
4 Separated by 150 miles of water or less
5 Separated by 400 miles of water or less


Questions and Feedback

The contiguity data sets are hosted by Paul Hensel, University of North Texas, under the COW Data Set Hosting Program. In case of questions or concerns concerning the data or coding rules, he may be contacted by email at