The things that happened between the Æsir and the Vanir are an interesting part of Norse mythology. While other cultures have had "elder" and "younger" generations of gods, as with the Titans and the Olympians of ancient Greece, the Æsir and Vanir were portrayed as contemporaries. The two tribes fought battles, concluded treaties, and exchanged hostages; Freyr and Freyja were said to be hostages. Some believe that events that occurred between the Æsir and Vanir were a reflection of events common between different Norse clans at the time.