The document system 108 can communicate with the knowledge panel system 110 to identify, generate, and serve knowledge panels to the user devices 106. If it is determined that a knowledge panel should be provided, the knowledge panel system 110 can generate a knowledge panel by applying historical data 111 and/or content items 112 to a template 113. The templates 113 include placeholder data and structure data that defines a particular type of knowledge panel. For example, for a map-type knowledge panel, a template 113 may include placeholder data for a title, latitude and longitude coordinates, and a map image. The placeholder data of the template 113 can be replaced with historic data 111 and/or content items 112. For the map template 113, the name, latitude and longitude, and map image of a particular city may be used, producing a particular knowledge panel for that city loaded with that city's information. Other types of templates 113 may use historical data 111. For example, for a knowledge panel related to a particular person, historic data 111 that includes an index of communication between that person and the user requesting the knowledge panel may be used. The historical data 11 can be presented as a visual time line that is clickable to any period that can provide related documents or information.

In some implementations, the knowledge panel system 110 may be a subsystem of a search engine that is accessible by a web browser. In other implementations, the knowledge panel system 110 may be a stand-alone system that operates independently of a search engine.