When the British took over Malta, they fully appreciated the military value of the Santa Margerita and the Cottonera Lines. However they were concerned that with the advances made in warfare, once the enemy penetrated the outer ring it could utilise the space in between the lines to inflict great damage upon the inner ring. Thus in 1853 the British bridged the Lines in the area known as il-Kastell or St Clement’s Retrenchment. This two storey defence system consisted of a blockade of more than 384 shotguns that would have been able to respond with enfilading fire along an enemy’s flank, and comprised of two entrances; St Clement’s, being the main back gate, and the Firenzuola or British Front Gate.

St Clement’s Retrenchment was primarily intended to link the Santa Margerita and the Cottonera Lines while also serving as an army barracks. For this reason, it is also known as Fort Verdala or Verdala Barracks. During the First World War, Cittadella Verdala served as a military confinement for prisoners of war and held several top German officials.

However by the time that the Retrenchment was completed, military warfare had advanced further, rendering St Clement’s military value practically obsolete and during both world wars, the building was mainly used as a centre of education for the children of British service personnel. Following that, the Barracks were adapted for residential purposes in order to meet the then acute housing shortage within the area.