Many thanks Sven and Martin, Svens suggestion (adding an AjaxEventBehavior("load")) works like a charm. Exactly what i was asking.
Now the next problem is with #de.agilecoders.wicket.core.markup.html.bootstrap.components.TooltipBehavior Allthough the resulting html is now perfect (img tag pointing to a usemap which is filled with areas, each containing a tooltip), no tooltip pops up. I have no idea what the cause may be, still debugging the Tooltip class and the corresponding JS. I will check Martins suggestion and give ClientSideImageMap a try. BTW: Once my code runs, i will be more than happy to contribute a code snippet to the wiki or to whatever document you regard more usefull. Regards Christos Stieglitz