The medieval Botcher gate in the town wall was replaced by the fortress called Carlisle Citadel by Stefan von Haschenperg, who was a Czech military engineer employed by Henry VIII of England in the 1540s.
Very little is known of Stefan's career, however he was mentioned as a gentleman of Moravia, and subject of Bohemia, in a letter from the Regent of the Netherlands to Henry VIII in 1544.[1] He spoke in Polish to sailors of a fleet of Charles V in 1539. He seems to have first offered his services as armourer and architect to Henry VIII in 1535; giving a note to the Duke of Suffolk to pass to Thomas Cromwell and the King.[3] Stefan was part of the design team for the device forts at Sandgate and Camber Castles, and the gun emplacements made of earth on the Downs. In November 1540 he went to the Pale of Calais. The French ambassador in London, Charles de Marillac, heard of this and reported to Francis I of France that the 'German' engineer had gone to design new bulwarks. Stefan 'the Almain' crossed the border into Ardres for a day to spy out the French fortification there for Henry VIII.
His connections with Carlisle began in July 1541, when he was made sole surveyor of the works at Carlisle, but was sacked by the Privy Council two years later for having, "lewdlye behaved himself," and spent a great treasure to no purpose.
Source & More Information: Wikipedia, Stefan von Haschenperg, http://en.wikipedia.org/wiki/Stefan_von_Haschenperg