Why did henry the 8th want a boy baby and not a girl?

Girls - or so it was thought - we weaker and could not rule with authority. Before Henry VIII's reign, there had only been one female queen, Matilda, and her reign had led to serious civil war.

Whilst a male king could have absolute authority, queens would have to be supported by male councillors and advisors, which Henry VIII thought would cause strife amongst the nobility. They were also thought to inspire rebellion against their rule, particularly among the more conservative members of society.

Put simply - he wanted the Tudor dynasty to continue, without risk of uprising or civil war.