Yes, I read that, and of course it is possible. Nevertheless the fact that the centralized government was unstable and news would not travel too fast makes me think that it is a bit strange nobody tried it in 150 years. The maps of France they present also shows that lots of territories would not recognize the French crown for long time. Those could have developed the technology and either take over the throne or give the crown one more reason to develop the technology themselves.<p>Maybe the line is thin, but given the long times it seems strange to me that there has not been at least an attempt to this (at least to my knowledge, but they don&#x27;t cite any such event).