By the early 12th century, the emperor convened the Diet (Hoftag) in imperial or episcopal cities more systematically, moving beyond ad hoc court meetings. This regular calling of assemblies provided a durable forum for princes and prelates to deliberate on imperial affairs.
Henry IV issues an empire-wide Landfrieden at Mainz (time-limited), an early attempt to curb private violence and stabilize legal order through an assembly-based proclamation—an important predecessor to later, more institutionalized Diet-driven peace legislation.
The Concordat of Worms ends the first phase of the Investiture Controversy by distinguishing spiritual and temporal investiture. Bishops and abbots were to be canonically chosen, while the ruler retained a role in contested elections and in granting temporal regalia—strengthening the political weight of ecclesiastical princes within imperial assemblies.
After the mid-13th century, representatives of imperial and episcopal cities came to be recognized in the Diet, broadening participation beyond princes and higher clergy and laying groundwork for later, more structured representation of the imperial cities.
Around the later 13th century, the electoral princes increasingly met as a distinct group within (and alongside) imperial assemblies, reflecting their special constitutional role in choosing the King of the Romans and foreshadowing later formal division into colleges.
The Declaration of Rhense (Kurverein) states that election by the electors (or their majority) confers royal authority without requiring papal confirmation. This strengthens the electors’ collective standing and helps define the constitutional relationship between election, legitimacy, and imperial governance.
Issued through Diet deliberations at Nuremberg and Metz, the Golden Bull of 1356 fixes the number and identity of the seven prince-electors, regulates election procedures, and entrenches key electoral privileges—providing a foundational constitutional framework that shaped later Reichstag practice.
Further negotiations at the Diet of Metz conclude and promulgate the final chapters of the Golden Bull on Christmas Day 1356, underscoring the Diet’s role as the venue where major constitutional settlements were negotiated and finalized.
From about the 1470s, assemblies increasingly came to be described (in hindsight and gradually in usage) as Reichstage rather than only Hoftage, signaling a shift toward viewing the Diet as a more distinct institution rather than merely an episodic court gathering.
By 1489, the Diet is described as divided into three colleges meeting separately—Electors, Princes, and Imperial Cities—a key step toward a more stable representative structure for deliberation and decision-making within the Empire.
The Diet of Worms (1495) becomes a landmark for Reichsreform, with broad participation by estates and structured negotiation through curiae. It is also associated with making the term Reichstag more common after its decisions, reflecting the Diet’s growing institutional identity.
The Ewiger Landfriede (Eternal Peace), proclaimed at Worms, establishes an open-ended formal ban on the traditional right of feud, marking a major Diet-driven effort to strengthen public order and channel disputes toward legal mechanisms rather than private warfare.
Development of the Imperial Diet (Reichstag) and representative institutions (1000–1500)
