From Wiki:
Europa '51 (also known as The Greatest Love) is a 1952 Italian neorealist film directed by Roberto Rossellini, starring Ingrid Bergman and Alexander Knox.
Irene (Ingrid Bergman) and George Girard (Alexander Knox) are a wealthy couple living in post-war Rome with their son Michele (Sandro Franchina). During a dinner party, Michele constantly tries to get his mother's attention, but Irene is more interested in being a good hostess to her guests than being an attentive mother. As a result, Michele attempts suicide by falling through a stairwell several stories, fracturing his hip.
At the hospital, Irene promises to never leave Michele and to be more attentive, but he dies soon after from a blood clot. Irene, shocked by her son's death, is bedridden for ten days, before enlisting the help of Andrea Casatti (Ettore Giannini) to help her overcome her grief. Being a communist, he takes her to the poorer parts of Rome and leads her into donating her time and money to help people there. While there, she gives the money for a boy's medical treatment, helps a woman with six children to find a job at a factory (where she has a life changing experience working for a day in order to fill in for the woman), and cares for a woman of bad reputation who is dying of consumption.
As a result of helping these people, she spends less and less time at home. Her husband comes to the conclusion that she is having an affair with Andrea, which causes her to leave him. In addition, she is picked up by the police after helping a boy who had committed a theft evade arrest (she had told him to turn himself in).
While in custody, the husband and the authorities decide to put her in a mental institution. At the end of the film, she is up for review on whether she would stay there permanently with the result being that her philosophy of helping people was dangerous for the fragile post-war society. Therefore, she becomes a permanent member of the institution.