As with many other Habsburg subdivisions there always lay open the chance that the two parts of the family might reunite at some future date. It was extremely unclear which of them should be seen as the senior branch: the Holy Roman Emperor trumps everyone, but it was impossible not to notice what was happening in Spain, now united fully and with a proper resident monarch at last, who in 1581 tacked on Portugal and its own American and Asian empires just for good measure. Both branches of the Habsburgs behaved as though they were senior, and this was a key factor in keeping them apart.
