The metric shows the evolution of the area of the selected super cluster during the selected war.

Cluster is a categorization that includes all iterations of a nation and all the possessions of this nation. Example: the cluster spain includes the iterations of that nation, like the Kingdom of Spain and the First Spanish Republic, whereas possessions of spain include Spanish America and the Spanish Philippines. Super cluster is a categorization that additionally includes the possessions of possessions. Example: A super cluster extends this categorization to include the possessions of a nation's possessions. For instance, during the Iberian Union, Spain not only controlled Portugal through a personal union but also acquired Portugal's colonies, such as Brazil, which are included in the super cluster for Spain.

An event (sometimes simply called war) is a categorization that encompasses changes, revolts, and other significant occurrences. Phersu Atlas includes all historical wars that involved changes or revolts, as well as a small percentage of non-war events (1% of the total), such as coastline changes and peace treaties.

You can apply a filter (from a specific year to another) to narrow the time range. Clicking on a point in the graph will provide further information.