Secessiones Plebis (Or the Plebeian camping trips)

The Secessions of the Plebs
EX TEMPORE
Four (?) times during the early history of the Roman Republic, large amounts of the lower classes (known as the plebs/plebeians because of the split between noble and common classes created by Romulus(?)) voluntarily separated themselves from the Roman state and were able to use their status as the backbone of the Roman agricultural and military base to negotiate from a position of power against the Senate and the aristocracy.
The first secession took place in 494 BC, when the plebs took camp on a nearby hill (because..?) and were only convinced to return due to negotiations carried out by Menenius Agrippa, who used a noteworthy metaphor of the plebs as the "belly" of the state, which should not rebel because a body needed to work together to stay solvent. Part of the terms of the return of the plebs was the creation of the Tribune of the Plebs, a sacrosanct yearly position filled by a member of the patrician class who could veto acts of the Senate, call together the concilium plebis and introduce legislation through it.

 The second secession took place in 454 BC in the face of unequal treatment of members of different social classes under the law, and resulted in the creation of the Twelve Tables, a publicly posted law code which attempted to ensure that legal justice would be carried out fairly regardless of the social position of the defendant and prosecutor.

The third secession took place in 387 BC during the war with the Gauls and an end to it was negotiated by Camillus, according to Livy (These are all according to Livy.).

The fourth secession...?

DOCTUS

The number of secessions of the plebs is debated; Cary and Scullard claim five. The lower classes (known as the plebs/plebeians, a split which has obscure origins; Livy traces the patricians to the descendants of Romulus' first senatorial families; the divisions were codified by Servius Tullius' divisions into social classes) voluntarily separated themselves from the Roman state and were able to use their status as the backbone of the Roman agricultural and military base to negotiate from a position of power against the Senate and the aristocracy.

The first secession took place in 494 BC, when the plebs took camp on a nearby hill (Mons Sacer) because of the harsh rule of Appius Claudius because of his harsh enforcement of debt laws. They were only convinced to return due to negotiations carried out by Menenius Agrippa, who used a noteworthy metaphor of the plebs as the other parts and the patricians as the "belly" of the state, against which they should not rebel because a body needed to work together to stay solvent. Part of the terms of the return of the plebs was the creation of the Tribune of the Plebs, a sacrosanct yearly position filled by a member of the patrician class who could veto acts of the Senate, call together the concilium plebis and introduce legislation through it (full explanation of the tribunate later).

The second secession took place in 449 BC in the face of unequal treatment of members of different social classes under the law, and resulted in the adoption of the Twelve Tables (which had been created and debated about by sets of decemviri the previous two years), a publicly posted but not comprehensive law code which attempted to ensure that legal justice would be carried out fairly regardless of the social position of the defendant and prosecutor.

The third secession is posited to have occurred in 445 BC to force the adoption of the Lex Canuleia, which permitted marriage between patricians and plebeians.

The fourth secession is noted by Livy as a military revolt in 342 BC.

The fifth secession occurred in 287 BC to force the adoption of the Lex Hortensia, which gave plebiscites the force of law.