Although Mdina was no longer the capital city , the Order still strengthened the city 's defences , and gradually upgraded its medieval walls into a gunpowder fortress . In the 1540s , during the magistracy of Juan de Homedes y Coscon , two bastions were built on the corners of the city 's land front . The central De Redin Bastion was built by Grand Master Martin de Redin in the mid-17th century . The city was damaged during the 1693 Sicily earthquake , and repairs were made over the course of the 18th century . During the rebuilding , the city 's entrance was replaced by a larger gate by the architect Charles François de Mondion in 1724 , and the last modifications were made in 1746 , when Despuig Bastion was completed . There were other plans to strengthen the city but these were not implemented as the Order focused on the fortifications at the harbour area
1693 Sicily earthquake
1693 Sicily earthquake
Fortifications of Malta