St. John and St. Cordula

The knightly order's first chapel on this site was built in 1239. In 1263 the commandery significantly expanded its landholdings and used the increased income to develop the settlement further. The church underwent several rounds of rebuilding: it was enlarged after a fire, completed by 1388, then altered again from 1422 to 1427 and once more after 1571 — a plan from that final phase survives in Arnold Mercator's survey of Cologne.

Bones discovered in a vineyard to the west of the site were identified in 1278 by Albertus Magnus as those of Saint Cordula. According to legend, she suffered martyrdom alongside Saint Ursula in Cologne; the church of St. Ursula stands close by. From 1331 onwards her relics were housed and venerated in a newly built chapel within the commandery.

Beneath a single steep saddle roof the church combined a Gothic double-nave, three-bay nave with an equally three-bay choir reserved mainly for members of the order. The northern aisle carried four tent roofs, with the clerestory buttresses set between them. The ridge was crowned with Hospitaller crosses; at the centre originally rose a tall Gothic flèche, later replaced by an onion-domed turret topped with a Hospitaller cross, its open lantern likely housing bells. A hexagonal stair tower projected from the west front, and a Passion cross bearing the instruments of the Passion stood before the commandery wall.

Following Napoleonic secularisation, public worship ceased in 1798, the commandery was suppressed in 1802, and the church was demolished in 1807. Some relics were transferred to St. Remigius in Königswinter. The Hospitaller presence lives on in the names Johannisstraße and Johannishaus nearby. In 1846 the Jakordenstraße was named after the church — "Jakorden" being the Cologne dialect contraction of Johannes and Cordula — while the adjacent Cordulastraße likewise bears the saint's name.