From WhyNotWiki

http://meta.wikimedia.org/wiki/Help:EasyTimeline_syntax

http://meta.wikimedia.org/wiki/Help:EasyTimeline_activation

[edit] Test

<timeline> ImageSize = width:400 height:150 PlotArea = width:400 height:150 left:0 bottom:0 TimeAxis = orientation:vertical # dummy, required Period = from:0 till:1 # dummy, required Define $s = fontsize:XL TextData =

 pos:(50,120) $s text:Leiden
 pos:(150,110) $s text:Alphen aan den Rijn
 pos:(10,80) $s text:The Hague
 pos:(50,40) $s text:Rotterdam

</timeline>