The Galactic Republic (–19 BBY), commonly known as the Republic, High Republic, and remembered as the Old Republic, was a federal parliamentary republic comprising thousands of worlds spread across the galaxy. It was ruled over by the Galactic Senate led by a Supreme Chancellor. This position was filled by Finis Valorum before Sheev Palpatine manipulated Queen Amidala into calling for a reelection in the Senate.
Throughout the Clone Wars, it began to collapse due to the corruption and injustice that spread within its government and caused many politicians and citizens to break away from the Republic and join the Confederacy of Independent Systems. By 19 BBY, the Republic had weakened enough for Palpatine to transform it into the Galactic Empire.
The Republic was eventually restored in 4 ABY after the destruction of the second Death Star during the battle of Endor, only this time, it was reorganised with the Rebel Alliance and formed the New Republic.