As early as 1527, the 4.5-kilometer-long Lend Canal was built to supply the city with water from Lake Wörthersee.
The development of the city itself began in 1534. Buildings were built within the newly constructed city walls that still characterize the face of Klagenfurt today. The Protestant Preacher's Church (later Klagenfurt Cathedral), built in 1581, the Lindwurm fountain, which was erected in 1593 on the New Square, as well as the country house, built between 1574 and 1594, which was intended to serve as the seat of the state parliament. It is still the seat of the Carinthian state parliament today.
The coat of arms room is located on the first floor of the Klagenfurt country house. When we enter, we are the only visitors for miles around. The room is 9.8 meters high and the floor area measures 23 × 13 meters, unchanged since 1581. The room was originally decorated with frescoes and a ceiling painting by Anton Blumenthal, but these were destroyed in a fire in 1723. The walls and ceiling were redesigned by Josef Ferdinand Fromiller, and since then only individual coats of arms have been added.
The wall frescoes, the ceiling fresco and over 665 coats of arms tell an impressive story of the power and influence of the Carinthian Estates. On the north wall there is a framed fresco from 1740, which shows the installation of the Carinthian Duke at Fürstenstein near Karnburg. Another fresco on the south wall shows the handing over of the gift letter by Maximilian I to the Carinthian Estates on April 24, 1518, which made Klagenfurt a state town. These frescoes symbolize the class and national consciousness of the Carinthian Estates.
The remaining walls of the hall are covered with 650 coats of arms, which together with those on the ceiling make a total of 665 coats of arms. The coats of arms of the nobility and knights can be seen on the long sides. In the top two rows are the family coats of arms that were part of the nobility before 1591, including those of the families that were admitted later, ending with Count Hugo Henckel-Donnersmarck in 1847. Some of the coats of arms are empty because the corresponding coats of arms could no longer be identified in the Baroque period. On the south side are the coats of arms of the ecclesiastical estates and the state governors, ending with Leopold von Aichelburg-Labia (1909–1918). The north side shows the coats of arms of the state vice-cathedrals and state administrators, offices that only existed until 1747.
The marble floor in white, red and black was created by the Venetian Francesco Robba, as were the door frames, the gate to the coat of arms room and the southern fireplace. The northern fireplace was reconstructed in 1908 by Pietro d'Aronco from Gemona. Since March 2006, the Prince's Stone, a symbolic element of Carinthian history, has once again stood in front of this fireplace.
Fromiller also created the wall paintings in the Small Coat of Arms Hall, formerly known as the Council Chamber, which still serves as the consultation and meeting room of the Carinthian State Parliament.
Here the walls show 298 coats of arms the burgraves, general collectors, state presidents, councillors and the last noble governors of Carinthia. The flat ceiling shows mock architecture and an allegorical fresco Veritas temporis filia (Truth as the daughter of time).
The meeting room, originally called the Landstube, was used as a meeting room from the beginning. Even today it is still used by the Carinthian State Parliament, mostly on Thursdays.
The large and small coat of arms halls as well as the conference room and Kolig hall can be visited during the summer months. The ground floor and parts of the basement now house the Gasthaus im Landhaushof restaurant.