Origins
Tribunal entered English in the 15th century from Latin 'tribūnal' (a raised platform for magistrates, a judgment seat), via Old French. The Latin word derived from 'tribūnus' (a Roman magistrate, originally a leader of a tribe), which in turn came from 'tribus' (a tribe, one of the traditional divisions of the Roman people).
The etymology reaches back to the legendary origins of Rome. According to tradition, Romulus divided the early Roman people into three tribes (trēs tribūs): the Ramnes, the Tities, and the Luceres. Each tribe was led by a 'tribūnus' — a tribal chief. The word 'tribus' likely connects to PIE *tri- (three), though some scholars have proposed alternative derivations. Over centuries, 'tribus' expanded from these original three divisions into the 35 tribes of the mature Republic, but the name preserved the memory of the original triad.
A 'tribūnal' was the elevated platform — typically a raised stone or wooden dais — from which a Roman magistrate sat to hear cases and render judgments. The physical elevation was both practical (making the magistrate visible to crowds) and symbolic (placing justice above the ordinary level of human affairs). The 'tribūnal' of the praetor in the Forum Romanum was one of the most important seats of justice in the ancient world.
Latin Roots
The tribune of the plebs (tribūnus plēbis) held extraordinary power in the Roman Republic. Created in 494 BCE after the plebeians seceded from Rome in protest against patrician dominance, the tribunes could veto any action by any magistrate, propose legislation to the plebeian assembly, and were considered sacrosanct — anyone who harmed a tribune was declared an outlaw. The tribune's power of intercessio (intervention) — the simple declaration 'veto' ('I forbid') — could stop any state action. This power, exercised from the tribunal, made the tribunes the most formidable check on Roman governmental authority.
The word 'tribute' is closely related. Originally, a 'tribūtum' was a tax levied on each tribe to fund public needs, especially military campaigns. The meaning shifted to any payment exacted by a conqueror from the conquered, and eventually to any expression of respect or admiration. 'Contribute' (to give together), 'distribute' (to give out separately), 'attribute' (to assign to), and 'retribution' (a paying back) all extend from 'tribuere' (to assign, to allot, to pay), the verbal form of 'tribus.'
In modern English, a tribunal is a court or judicial body, often one established for a specific purpose outside the ordinary court system. War crimes tribunals, employment tribunals, immigration tribunals, and international tribunals all use the word to describe bodies that hear cases and render binding decisions. The International Criminal Tribunal for the former Yugoslavia (ICTY) and the Nuremberg Tribunal are among the most historically significant.