Similar to the lists of timelines by era and by country, this is a list of timelines by theme. Certain specific themes are rather popular in the genre of alternate history. This page wants to make it easier to find an AH.com timeline based on its thematic background. A thematic background usualy represents a focus of the timeline on one particular area, while not ignoring the rest of the baggage that comes with it. The are the TL is focused on can be anything from geography, biology, politics, (popular) culture, art, sports, technology, etc.