Sinzig received its first official recognition in 762 A.D. On 10 July that year, King Pippin the Younger, the father of Charlemagne, presented a certificate of his decree in the Palace of Sinzig (Sentiaco Palacio), officially recognizing the town as "Sentiacum."
Abraham of Augsburg; a convert to Judaism, along with 61 other Jews, were slain in a pogrom in Sinzig in 1265.[3]
Sinzig first received its rights as a town on 9 October 1267.
Twice, the medieval town, which since 1300 has been protected by a massive wall, was almost entirely destroyed by fires, one in 1583 and another in 1758. Little of the wall now remains, as industrialization and urban development led to its nearly complete loss at the end of the 19th century. After World War II, Sinzig experienced a population explosion and soon evolved into an industrial town.
With the district reform of 1969, Bad-Bodendorf, Franken, Koisdorf, Löhndorf, and Westum became provinces of Sinzig. Today, Sinzig, together with the town of Remagen, have developed a modern consumer centre, with multiple schools and shopping centres.
The Sinziger Schloss (Sinzig Castle) was built in the period of the Rhine Romantic. Between 1854 and 1858, a businessman, Gustav Bunge of Cologne, ordered the erection of a summer villa in Sinzig in the style of a neo-gothicpalace. Surrounding the palace is a garden, constructed in the style of a Romantic park. The castle has since then become a museum.