In 1883 the British Government installed a single 100-ton gun: a 450 mm rifled muzzle-loading gun made by Armstrong Whitworth, at the battery by Rosia Bay that they named Napier of Magdala Battery after Field MarshalRobert Napier, 1st Baron Napier of Magdala, who had served as Governor of Gibraltar from 1876 to 1883. Earlier, in 1879, they had mounted another such gun in Gibraltar at Victoria Battery. These two batteries, together with two in Malta, were a response to the Italians having, in 1873, built the battleshipDuilio, which was to receive four Armstrong Guns of the same design. The British authorised the construction of Victoria and Napier of Magdala batteries in December 1878; they completed Victoria in 1879 and Napier of Magadala in 1883, at a total cost of £35,707. Because the British viewed the two batteries as part of the one large fortress that was the Rock of Gibraltar, the batteries lacked all-round protection and any of the close-in defences such as the dry moats with caponiers or counterscarp galleries that the British installed at Cambridge Battery and Fort Rinella, both of which were free-standing pentagonal forts. The gun that is now at Napier of Magdala Battery originally armed Victoria Battery, but the British moved it to Napier when the original gun there split during firing practice. The gun at Napier Battery received the nickname, "The Rockbuster". During World War II, the British Army stationed a battery of four 3.7" and two Bofors quick-firinganti-aircraft guns at the site. In 1945 they almost fired upon an Iberia AirlinesJunkers Ju 88 that had wandered into Gibraltar's airspace while on a flight from Málaga to Tetouan. The "Rockbuster" was last fired in 2002 to mark the 2002 Calpe Conference between Gibraltar and Malta.
Philately
In 2010 Gibraltar and Malta jointly issued a four-stamp set of stamps featuring the two countries' 100-ton guns. Two stamps show the gun at Napier of Magdala Battery, and two the gun at Fort Rinella. One of each pair is a view from 1882, and the other is a view from 2010. The stamps from Gibraltar bear a denomination of 75 pence, while those from Malta bear a denomination of 0.75 euros.