1590 Demi-Culverin C12 Londonderry

Thomas Johnson Demi-Culverin cannon found defending the siege city

Demi-Culverin Londonderry NI
Demi-culverin Cannon

A gun found on the ramparts, designated ‘C12’, a demi-culverin of 10ft dating to 1590 and bearing the mark of Thomas Johnson, Queen’s founder of iron ordnance.

Analysis of this piece revealed that it may have been one of those sent to Sir Henry Docwra at Derry to assist him with his Foyle campaign.

If so, then this demi-culverin represents a remarkable survival from a crucial period of the Nine Years War, and has grown old with the city over 400 years as it developed from an Elizabethan military base into what eventually became the Maiden city.


Type: Demi-Culverin
Gunfounder: Thomas Johnson
Cast: 1590
Distinguishing marks: Rose and Crown (c12)
Bore: 4.5″ (114mm)
Length: 120″ (3048mm)
Weight: 3417lb (1550kg)
Location: Londonderry, Northern Ireland
Display notes: Cast in 1590 by Thomas Johnston* Founder of Iron Ordnance to Queen Elizabeth I. *mispelled