The hillfort is one of the oldest historical landmarks in Gaujiena.

Approximately 1,000 years ago, the first inhabitants of the Gaujiena area settled here. In ancient times, north-eastern Latvia was divided into two political territories – Tālava and Atzele. The surroundings of Gaujiena were mainly inhabited by Latgalians, with smaller groups of Estonians and Livonians. Ancient Latvians built their castles in locations that were difficult to access, typically on sites with steep slopes.

• The name Atzele was first mentioned in 1111 in the Novgorod Chronicle, describing Prince Mstislav’s military campaign against Atzele, from which he returned with rich spoils.
• 1224. In the spring of 1224, after a siege and attacks, German forces captured and burnt the Latvian wooden castle. The German Army included many knights as well as religious preachers. The conquered lands were divided among them, and Atzele came into the hands of the Order of the Brothers of the Sword.
• 1236. In 1236, German knights began constructing their stone castle on the site of the former ancient Latvian castle.
• Ancient Latvians built their castles as log structures made of timber. Around the castle stood a large defensive rampart composed of vertically placed logs. The Crusaders built stone castles, usually from boulders. There weren’t many boulders in Gaujiena; however, there were layers of dolomite close to the surface. To build the castle, German knights forced local Latvians into labour. One group quarried dolomite, while others transported it to the hillfort. A high stone wall, 1.5 metres thick, was built around the entire hillfort. Many craftsmen were brought from Germany to supervise the work.
• Special guard rooms were built into the castle’s defensive walls, where watchmen stood on duty around the clock to monitor for possible attacks.
• 1558. In 1558, during the Livonian War, the castle of Gaujiena was destroyed by the Russians. Poland and Sweden later intervened in the Livonian War, until Poland won, forcing Russia to withdraw.
• Between 1582 and 1600, during the rule of the Osobļinski family, the ruined castle was restored.
• 1625. In 1625, the Swedes won the war, and King Gustavus Adolphus of Sweden granted Gaujiena Manor to his Reichsmarshal Axel Banér, who later passed it on to his daughter.
• 1700. gadā sākās Ziemeļu karš, kurā atkal uzvarēja krievi. Krievijas cars Pēteris І šeit ieradās 1702. gadā un viņa karavadonis Šeremetjevs nopostīja pili tā, ka to atjaunot vairs nebija iespējams.