The king underwrote the journey of Spain's prince.
The king underwrote the journey of Spain's prince's.
We have a double possessive here, we are referring to the journey of the prince of Spain. How do we express that in a sentence? If I were refer, say, to a house that belongs to may uncle I would say "the house of my uncle's". For this reason I think the second sentence is correct but it sounds a bit odd. Can you help me?