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Derby Fort

Also known as, or recorded in historical documents as;
St Michaels Island; Fort Island

In the parish of Malew.
On the Isle of Man.

OS Map Grid Reference: SC29656748
Latitude 54.07499° Longitude -4.60503°

Derby Fort has been described as a certain Artillery Fort.

There are major building remains.

This site is a archaeological monument protected by law.


The 7th Earl of Derby put a datestone of c.1644 into the Round Fort but it had then been standing for over a hundred years (O'Neil 1951).
Derby Fort built by James 7th Earl. A round stone fort; over the gateway is a stone bearing the date 1645. In this fort are cannon collected from different parts of the island (Kermode 1930).
One of Henry VIII forts which he built about 1540.
A castellated round stone built tower situated on a peninsular. It has a diameter of 24.0m with walls 3.0m thick. In the interior are the remains of a rectangular free standing building of unknown date. In recesses in the wall in north and north-west are six cannons covering the entrance to the bay. In the south west is a doorway 1.3m wide. The fort is well preserved and is a typical Henry VIII fort. A plaque indicates that this is a protected monument. Above the doorway is a sandstone block with the remains of an embossed coronet and the date 16--. It is no longer used as a lighthouse.
Derby Fort, a circular stone built fort (normally locked) on St Michael's Isle, which gives the islet its alternative name, Fort Island. Originally built about 1540, as part of Henry VIII's scheme of coastal defence against threat of invasion, the fort was reconditioned in Civil War times by James, 7th Earl of Derby, whose initials and the date 164(?) appear on a tablet above the entrance. (see SC 26 NE 17 for rectangular battery to the south-west) ( Anc. and Hist. Mons. 1967; Curphey 1967)
Derby Fort, correctly portrayed on OS maps and the structure itself is in good order (oral information). (PastScape)

Round stone fort, partly covered in, for seven big guns. Built about 1540 (Its character suggests a Henrician date; it is certainly not like normal Civil War work.); reconstructed 1645 (see Moore. IOM.i. 247, quoting from the Liber Scaccarii of the Isle. This concerns the ordering of a fort on St Michael's Island, and might be taken as referring to the building of the round fort, which has a tablet over its doorway inscribed 164-. There is, however, an earthwork near by, and this may well be the fort of 1645, especially as the stone fort has been altered internally ( ex inf. A.M. Cubbon). (King 1983)

Comments (by Philip Davis)

The Tudor date for this tower is based on form, there being no historical evidence.
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This record last updated on Tuesday, April 18, 2017