The Collective Triumvirate Creed

The The Collective Triumvirate Creed was the founding document and highest set of laws in the Galactic Triumvirate. The Constitution was written in 19 BBY to unify the Triumvirate systems, and it is widely believed that the same Constitution existed throughout the Triumvirate existence.

Overview
The Constitution invested executive powers in the General Ministry and Triumvirate Senate, legislative powers in the Triumvirate Senate, and judicial powers in the Supreme Court and the Regional Courts. It placed the Triumvirate capital at Shikaakwa, set its official language as  Galactic Basic Standard), its official currency the Triumvirate  Standard Credit. It made the Triumvirate Chancellor Head of Government and the Minister of Defense Commander-in-Chief. The Senate was granted the authority to levy a military and to regulate trade. The Constitution had strict provisions against persecution of one's personal beliefs.

Two notable clauses of the Constitution were the Rights of Sentience and Contemplanys Hermi. The first provided the rights all citizens in the Republic were entitled to, and included the formal outlawing of slavery; the second allowed for the Corellian system to enact temporary autonomy in exchange for withdrawal from the Senate. The Coruscant Accords, possibly part of the Constitution, determined guidelines for Republic membership. By the timeof the Galactic War, thirty-six wartime provisions were listed in the Constitution, and Supreme Chancellor Leontyne Saresh enacted all thirty-six of them within days of her election.

The Emergency Powers Act, passed in 24 BBY, contained (among other things) an amendment to the Constitution that eliminated term limits for Supreme Chancellors, giving them the choice of when to stand down. During the Clone Wars, the Constitution was increasingly modified by the Senate (among whom a supermajority were loyal to Palpatine) including the controversial Fourth Constitutional Amendment and granting more powers to the executive branch. This led to the establishment of the Galactic Empire.

The Galactic Constitution presumably was the basis for the Imperial Charter, no doubt with several major changes including the nature of the executive branch, military, law enforcement, and the Rights of Sentience. Whatever constitution the Empire used was presumably overridden by the state of emergency declared in 0 BBY. Later, the New Republic would develop a new constitution that, although somewhat different, was based on the Old Republic's.