There is almost no information on the duties the men of the 4th WIR were required to perform while in Gibraltar, though one might reasonably expect them to have undertaken sentry duty and manned defensive positions. Some of the soldiers had families with them: 75 women and 60 children arrived with the regiment in 1817. Regimental court martial records also reveal that some men stole from each other and from the regimental supplies, others drank or gambled too much, failed to turn up for duty on time, or got into arguments with their superior officers. The court martial records of white regiments are full of similar minor offences and nearly everyone was punished by a set number of lashes up to a maximum of 300. By far the most serious case was that of Private Richard Greenville, convicted of the murder of a fellow soldier. Greenville's death sentence was commuted by the Governor, most probably because he was only 17 or 18 years old at the time, and he was discharged and transported back to the West Indies.
The soldiers of the 4th WIR complained of the cold as soon as they arrived. Coming from a Caribbean climate where temperatures rarely dropped below 20 degrees Celsius, even at night, Gibraltar in late February was a shock. For long periods a ‘cold easterly’ wind accentuated the difference between tropical and temperate climates to men dressed “according to the West India fashion”. Extra clothing was distributed, “to an extent that would have been burthensome to others.”
If the hope had been that African soldiers would prove more robust than their European counterparts in Gibraltar it was quickly dashed. The men fell ill in large numbers, not from fever but from a variety of chest complaints, the most serious of which was consumption, or tuberculosis. On 26 May Major Nixon reported that 74 of the men were sick, while a further 65 were ‘invalids.’ Sixteen soldiers had already died in the 10 weeks since the regiment arrived. Physicians who had served in Gibraltar were well aware of the high incidence of pulmonary complaintsin the garrison. John Hennen, who was stationed in Gibraltar in 1809 and 1810, described “pulmonary affections” as the “true epidemic of the rock.”
By the end of 1817 the impact of the move to Gibraltar on the health of the men of the 4th WIR was becoming clear to all. The number of sick had declined to 43 but the number of ‘invalids’ – men who would never return to soldiering had climbed to 112. In early January 1818 sixty-seven of these ‘invalids’ boarded a transport ship for Barbados. During 1818 the number of sick gradually declined, but the death toll continued to mount, reaching 75 in December 1817. Most died of lung complaints: tuberculosis spreads easily via coughing in poorly ventilated spaces containing large numbers of people. Gibraltar's barracks easily met this criteria. When the regiment finally left Gibraltar on March 9th 1819, heading for disbandment in Sierra Leone, 120 soldiers had perished. Thirteen sick men were left behind in Gibraltar, to be absorbed into the white regiments when, or if, they recovered.