How can David Galula’s theory of counterinsurgency warfare be used to deepen the understanding of the British counterinsurgency during the Irish War of Independence? The Irish War of Independence occurred between 1919 – 1921 and was a guerilla conflict between the Irish republicans (the Irish Republican Army) and British forces in Ireland. The previous research conducted has mostly focused on the IRA and the Irish side; therefore, this study uses David Galulas theory about counterinsurgency to gain a deeper understanding of British counterinsurgency during the Irish War of Independence. This study employs a qualitative text analysis with a theory-consuming approach. The result of the study shows that David Galula’s theory does help with developing a further understanding of British counterinsurgency during the war. The theory shows clear signs that the British counterinsurgency wasn’t fit for conducting counterinsurgency-operations and there was a lack of understanding regarding the nature of the conflict. This research may therefore deepen the understanding of the Irish War of Independence, based on the drawn conclusions that the British forces was not equipped with the knowledge and skillset to conduct counterinsurgency.