Actually dowry could include anything, from very basic goods, to powerful alliances, depending on the status of the bride.
The thing is that if a prince wold marry a princess in medieval times, it was understandable that this would also bring an alliance with the families that were now united. While this may have not been an official dowry, it came with it nevertheless.
Most commonly though, women would bring money, goods, and property as their dowry, depending on the status of the family.
