It stood for power and strength, as well as for a royal attitude. Lions adorned flags and coats of arms, and somtimes wored and symbol were merged into the name of a powerful aristocrat.
Take for example Henry the Lion, Duke of Saxony (1130?-1195) or the english king Richard the Lionheart (1157-1199). The church appreciated lins as well. Numerous medieval bronze doors are adorned with lion heads as defensive and protective symbols. Still more imposing are lion gates, which can especially be found in Italy. Only occasionally did they find their way to other countries.
Imperial Cathedral in Königslutter
This symbolizes that the powerful have to submit to the Church. A different variant (e.g. found in Matera Cathedral) shows the lions holding human figures beween their pwas. This underlines danger, yet nevertheless implies that these too have to serve the Church.