It would be cool if they did, but they didn't. As such there is a controversy as to whether there might have been one or two, especially when a son with the same name succeeded his father.
Demetrios 1 and Demetrios 2 (First two kings of the IndoGreeks) are often thought to be one person and even the existence of the later is doubted.
See...
http://en.wikipedia.org/wiki/Demetrius_II_of_India
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