Legal Definitions - si prius

Si prius is a historical Latin legal phrase meaning "if before." It was traditionally used in writs, which are formal written commands from a court, particularly those related to summoning juries or scheduling trials. The phrase indicated a conditional instruction, often concerning whether judges had already arrived at a specific location to preside over cases or if a particular procedural step had already occurred.

• Imagine a scenario in medieval England where royal judges traveled on circuit to hear cases in various counties. A writ might be sent to a local sheriff, commanding them to summon a jury for an upcoming trial session, si prius (if before) the King's justices of assize had not already arrived in the county town.

  This illustrates si prius by making the sheriff's duty to summon a jury conditional. The jury was only to be summoned if the circuit judges had not yet reached the town, implying that their prior arrival might alter the need for or timing of the local jury's presence.

• Consider a historical court order concerning a complex land dispute. The order might stipulate that the case should be heard by a jury at the next scheduled assizes, si prius (if before) the parties had not already reached an out-of-court settlement or if a single judge had not already resolved a preliminary legal point that made a full jury trial unnecessary.

  Here, si prius establishes a contingency for the jury trial. The instruction to proceed with a jury trial at the assizes was valid only if certain prior conditions (like a settlement or a judge's preliminary ruling) had not already occurred, which would negate the need for the jury.