The original complex dates back to the 11th century and belonged to the Salians. Because it was built in a strategically favourable location on the Hambach Schlossberg, it dominated the trade routes crossing near Neustadt and also the northern route of the front Palatinate section of the Jakobsweg (Route of St James) , both, as a protective castle and as a robber baron's castle.
The bishop of Speyer John I († 1104), who was related to the Salians, bequeathed the castle to the diocese of Speyer, to whom it belonged for centuries until the end of the feudal period. - In 1552 troops of the margrave and mercenary leader Albrecht Alcibiades conquered the castle and burned it down. Bishop Marquard von Hattstein carried out a makeshift reconstruction. From then on the castle was used by a bishop's forester as his domicile. During the War of the Palatinate Succession, the ailing fortress was burned down by the French in 1688 and remained a ruin. Only the castle chapel dedicated to Saint Michael was rebuilt and consecrated again on 9 July 1723. French revolutionaries plundered it again on 30 July 1794 and destroyed it. They tied the figure of the Archangel Michael, previously venerated by the faithful, to the tail of a horse and rode it through the streets. The entire castle ruin fell first to the French state, later to the Kingdom of Bavaria.
In 1832, the castle ruins became the scene of the early efforts for democracy on German soil during the six-day protest event (27 May to 1 June 1832), the Hambach Festival of about 30,000 people.
The reason was the dissatisfaction of the Palatine population with the repressive measures of the Bavarian administration. In the years after 1816, the administration had taken back important achievements which had been granted to the people during the time of the occupation by France. After the Bavarian authorities had introduced strict censorship and banned political rallies, the organizers issued the event as a "Volksfest". The Palatine people found support from numerous other ethnic groups and individuals. Since that festival, Hambach Castle has been regarded as a symbol of democracy throughout Germany.