During the 8th century, Charles Martel kept king Theuderic IV prisoner in the castle of Otmus. At this time, the town took the name of Castrum Theodorici, later transformed in Château-Thierry (Castle of Thierry, Thierry is the French or early Roman language translation of Theuderic). In 946, the castle of Château-Thierry was the home of Herbert le-Vieux, Count of Omois of the House of Vermandois & Soissons.
In 1060, Hughes Lambert leveled the top of the hill. The castle of which we see the present-day ruins was founded in the 12th century by the Counts of Champagne. Château-Thierry Castle was rebuilt between 1220 and 1230 by Theobald IV, Count of Champagne, and until 1285 fell under the Lords of Coucy. After that date the castle was part of the royal domain, and then ceded in the early 15th century to Louis I, Duke of Orléans. After his death in 1407 the castle returned to the royal domain.
During the 15th and 16th century the castle was adapted to the use of firearms. The town and castle were taken by the English in 1421 and in 1544 by Charles V, the Holy Roman Emperor.
The Duchy of Château-Thierry was later given to the Bouillon Family, who left it without proper maintenance, causing the castle to fall into ruin.
At present you can see the remains of an enclosure which was defended on the north side by a wall with 8 circular towers with arrow slits, dating back to the early 13th century, and on the south side by a wall with rectangular towers with breeches for guns. One of these towers contains a staircase leading into the gardens. There are also remnants of the gate and the Roman keep and foundations of several other buildings to be seen. The size of the enclosure is very large so this must have been a formidable castle.
At present the site of Château-Thierry Castle can be visited freely during daytime.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.