Magyar Posta is issuing a stamp to commemorate the entry into service of the SMS LEITHA MONITOR 150 years ago. The numbered commemorative souvenir sheet designed by the graphic artist Glória Hefelle was produced in perforated and imperforated editions by Pénzjegynyomda Security Printing Company. The new issue will be released on 17 May 2022. It will be on sale at first day post offices and Filaposta in Hungary and may also be ordered from Magyar Posta’s online store from the date of issue. SMS LEITHA, often called the LAJTA MONITOR, is the oldest Austro-Hungarian warship which is still afloat. On 20 August 2010, the vessel was ceremonially renamed the LAJTA MONITOR SHIP MUSEUM. She was built in Hungary between 1870 and 1872. The warship was launched on 17 May 1871, entered service on 13 October 1872 and went into action on 8 December 1876, when she and her sister ship (SMS MAROS) engaged in a firefight with the then Turkish-held Belgrade fortress. She was deployed several times during the First World War. For more than 70 years, from the 1920s until 1994, she was used as an elevator ship for river control on the Danube. During its service it was renovated, rebuilt and modernised many times, but the structure of the original hull was not significantly altered. On 1 November 1992, she was declared a protected ship, and from 6 October 1993 the vessel became part of the collection of the Military History Institute and Museum. With extensive national cooperation and European Union funding, she was restored to her 1888-1893 condition in several stages between 1996 and 2010. The LAJTA MONITOR MUSEUM SHIP is a relic of military technology and military history of international significance, the oldest armoured warship for river duties in the world, and the honorary flagship of the Hungarian Defence Forces. The stamp of the souvenir sheet shows a picture of the former ship at the top and, below it, structural drawings of the side elevation and top view in reversed directions. The design of the frame of the souvenir sheet shows the restored ship with the Parliament building in the background, indicating that this internationally important technical and military history monument has been moored in front of the Parliament since 2014 as a museum ship that can be visited during the tourist season. The first day cover of the souvenir sheet features an enlarged image of the former monitor shown on the design of the stamp. The postmark shows a stylised design referring to the service seal of SMS LEITHA.