What was the relationship between the public assemblies and the tribune in
the roman republic?

Military tribunes were originally infantry commanders. Under the early republic there were six to a legion; some were appointed by the consuls (chief executives) or military commanders, and others were elected by the people. Under the empire he military tribunate was a preliminary part of a senatorial or an equestrian career and subject to the emperor’s nomination. Tribunes commanded bodyguard units and auxiliary cohorts.

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the main reason that the constitution did not proclaim all men to be free and equal is because of the issue of slavery.