Trade spread the italian renaissance across europe by merchants become patrons. monarchs become artists. merchants become politicians. artists become patrons

The answer is helping merchants become patrons.
Patrons refers to The person or institution that give financial support to a certain cause or artist.
Because of patrons, the artists in the renaissance period could solely focus themselves on creating their artwork without having to worry about meeting ends meet, and accelerate the spread of the renaissance culture.

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.