Complex sentence: At the beginning of French colonization, some Arab tribes, such as the "Bani Amir", opposed the French, fighting under the command of Emir Abd el-Kader in the western regions of Algeria.
Split into simpler sentences: At the beginning of French colonization, some Arab tribes, such as the "Bani Amir", oppose the French. And they engage in fighting under the command of Emir Abd el-Kader in the western region of Algeria.