This paper deals with a series of fatwas contained in al-Mahdi al-Wazzani’s Mi’yar al-Jadid on the legitimacy of ‘Abd al-Qadir b. Muhyi al-Din al-Jaza’iri’s armed resistance to the 1830 French invasion of Algeria. The Moroccan Sultan ‘Abd al-Rahman had initially participated in ‘Abd al-Qadir’s jihad but had soon been forced to withdraw his troops after having suffered heavy losses. Rather than lose religious prestige by being seen to have abandoned the duty of jihad, the sultan sought to subcontract the duty of jihad to ‘Abd al-Qadir. This unprecedented action was to cause the sultan great difficulties as his truce with the French depended upon his ability to reign in ‘Abd al-Qadir’s forces and prevent them from using his land and resources to attack them. If he could not fulfill this responsibility, his treaties with them became void and his land stood in danger of a French invasion. If, on the other hand, he crushed ‘Abd al-Qadir’s forces, he would not merely be unpopular among his subjects but would have appeared impious as he would have been seen to have impeded a religiously obligatory, defensive jihad which merely sought to retain lands previously governed by Muslims? In desperation, the sultan requested the jurists to write fatwas on what his duties were in this regard. In their fatwas, the jurists debated how apparent conflicts between the laws of Islam and the will of the sultan are to be resolved. They also discussed the extent to which the religious legitimacy of ‘Abd al-Qadir’s jihad was dependent upon the approval of the sultan. In response to the new dangers of colonialism, they re-evaluated classical teachings on defensive and offensive jihad, on whether jihad was a communal or an individual obligation and on the law of truces. I discuss how they drew on the legal precedents included in al-Wansharisi’s Mi’yar al-Mu’rib and on other earlier Maliki sources and how they sometimes radically altered these teachings in response to the exigencies of the Colonial Age. The jurist’s formulations of these debates were to set the ground for later discussions in other Middle Eastern countries regarding the appropriate response to Western colonialism.