When he was a few months old, film-maker Mickaël Bandela was put into the care of his foster mother Marie-Thérèse, after his own home was deemed unsuitable for the wellbeing of a small child. Throughout the next decades, his birth mother Gisèle remained a loving presence in his life. At the same time, the erratic infrequency of her visits left deep wounds on Bandela’s sense of self, scars that were reopened when he welcomed his first child. A soul-baring work of searing authenticity, Bandela’s searching documentary grapples with the complexities of motherhood and the long shadows of family trauma.

Bandela’s voiceover acts as an emotional compass and a guiding force throughout the film, which stitches together interviews with his two maternal figures, family photos, and various home and personal footage shot over the course of three decades. By charting both Bandela’s and Gisèle’s life trajectories, the dynamic editing reunites mother and son, even in the years when they were largely apart. The director also punctuates his family archives with reports from social workers on various stages of his growth, another impactful stylistic choice. The contrast between the impersonal tone of these notes and the richness of Bandela’s experience shows how, even with the best of intentions, government officials can fail to grasp the full extent of the challenges faced by a foster child.

Moving through time, the film also makes a crucial detour from Bandela’s life in France. On a poignant trip with Gisèle to her childhood home in the Congo, Bandela discovered the long history of neglect and displacement that had passed through generations of his family. In the context of such painful rifts, the title of his documentary carries a unifying significance; it is a beautiful tribute, not only to Marie-Thérèse and Gisèle specifically, but also to the sacrifices made by Black mothers everywhere.

• One Mother is on True Story from 8 November.