Why did the pope deny henry viii's annulment?

Before Henry VIII married Catherine of Aragon he received a Papal Bull from thePope agreeing that Henry could marry his dead brother's (Prince Arthur) wife. WhenHenry and Catherine married in June 1509 both were Roman Catholics.

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.