The 4th and 5th (Extra Reserve) Battalions joined other battalions in coastal defences of England due to an invasions scare, 4th to Redcar Yorkshire, the 5th to North Shields County Durham. Both battalions who were popular during their stay, returned to Ireland by the end of 1915, 5th assigned to the Curragh, 4th to Fermoy, then to Bere Island in February 1916. All three reserves were now at the location they would occupy for most of the war, the 3RMF with 76 officers and 1927 men being by far the strongest battalion (the other two comparatively weak with 500 men). Unless used as replacements for battalions in action, none of the RMF Reservists died during the war other than by accidents, sicknesses or natural causes. Nor were any killed during the 1916 Rebellion, although some RMFs were dispatched to Dublin from the Curragh, others to Wexford and to Galway.