It is thought that the Trsat castle lies at the exact spot of an ancient Illyrian and Roman fortress. It was owned by Frankopan family who built the present castle in the 13th century.
The capture of the Castle of Trsat compelled the Ban of Croatia, Andrew Bot of Bajna (Bajna is a village in Hungary, near Esztergom), to intervene in the Austro-Venetian war, and in June 1509 he first recaptured Trsat with his Croatian army and then entered Rijeka after expelling the Venetians. In October 1509, the Venetians withdrew for good and Rijeka returned to the possessions of Maximilian of Habsburg. This notable episode is the sole event which links Rijeka with Venice, and consequently with Italy, during the whole of its history from the 7th century on.
In the 17th century the castle fell into decay due to the receding threats from Venice and the Ottoman Empire. Its decline was accelerated by the earthquake of 1750. In the year 1811, during the Napoleonic wars, Captain Hoste in pursuit of the French, arrived with his frigate at Fiume where he made himself lieutenant-governor. The situation in Trieste soon drew him away, but in 1826 he had the satisfaction of handing the castle over to Field-Marshal Nugent, an Irishman then commanding the Austrian troops in the vicinity, for the purpose of conferring on him the rank of an Austrian noble. The general was later honoured by the Austrians and presented with the castle at Trsat as his residence. He had it restored in Neo-Gothic style and built a mausoleum adorned with the coat of arms of the Nugent family. It remained in the Nugent family until nearly the end of the Second World War when the general's great-granddaughter, Countess Nugent, died at the age of 82.
Today the castle has now been turned into a restaurant and many tourists visit the place during the summer months.
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.