Kętrzyn [ˈkɛntʂɨn] ( listen) (German: Rastenburg, from Lithuanian and Old Prussian Raistpilis - "a castle in the swamps") ( listen); until 1950 Polish: Rastembork), is a town in northeastern Poland with 28,351 inhabitants (2004). Situated in the Warmian-Masurian Voivodeship (since 1999), Kętrzyn was previously in Olsztyn Voivodeship (1975–1998). It is the capital of Kętrzyn County. The city was named after Wojciech Kętrzyński in 1950.
The original inhabitants of the region was the Balt tribe of the Aesti, mentioned by Tacitus in his Germania (AD 98). The town, known in German as Rastenburg and in Polish as Rastembork, was established in 1329 in the Monastic state of the Teutonic Knights and was granted town rights in 1357 by Henning Schindekop.
Rastenburg and the surrounding district was the scene of the First World War's first and second battles of the Masurian Lakes. During the Second World War Adolf Hitler's wartime military headquarters, the Wolfsschanze (Wolf's Lair), was located in the forest east of Rastenburg. The bunker was the setting for the failed 20 July plot against Hitler. In 1945 the area suffered devastation from both the retreating Germans and advancing Russians during the Vistula-Oder campaign. Some ruins of the Wolfsschanze remain. The town itself served as a Wehrmacht garrison town until it was occupied by the Red Army in 1945.
After the war, it was taken over by Poland, as provided for by the Potsdam Conference. Its surviving German residents who had not evacuated were subsequently expelled westward and replaced with Poles. The town was renamed Rastembork in 1945, and in 1950 to Kętrzyn after the Kashubian historian and activist Wojciech Kętrzyński.
- Karl Bogislaus Reichert, German anatomist of the 19th century.
- Elisabet Boehm (1859–1943), women's rights advocate
- Arno Holz (1863–1929) poet and dramatist
- Wilhelm Wien, physicist who received the Nobel Prize in physics in 1911 for his work on black body radiation. He was a cousin of Max Carl Wien, also a physicist.
- Rüdiger von Heyking (1894-1956), Luftwaffe general
- Waldemar Grzimek (1918–1984), sculptor
- Siegfried Tiefensee (1922–2009), composer
- Krzysztof Dariusz Szatrawski (1961-), writer, philosopher, poet
International relations 
Twin towns — Sister cities 
Kętrzyn is twinned with:
External links 
Coordinates: 54°05′N 21°23′E / 54.083°N 21.383°E