The most entitled person to a child's custody

Custody Fatwa no. 14806 All Praise be to Allah Alone. May peace and blessings be upon the Last Prophet. The Permanent Committee for Scholarly Research and Ifta' reviewed what was sent to His Eminence the President of the Permanent Committee for Scholarly Research and Ifta' from His Excellency the undersecretary of the Foreign Ministry for political affairs raised to the Committee by the General Secretary of the Council of Senior Scholars, number (3748) dated 10/9/1411 A.H. He posed a question stating:The embassy of the Kingdom of Saudi Arabia in Athens reported that Dar Al-Ifta' (the House of Fatwa) in the north of Greece informed it that an argument arose between a husband and his wife, which led to divorce. The couple has three children including a girl (who is five years old) and a boy (who is nine months old). The father wants to be given the custody of the children, but the mother and her parents see that the children are still underage and that it is better for them to stay with their mother. This is because their father is always busy with his job and his business in selling and buying real estate. Also, he spends the evenings with his colleagues and returns home late at night. Moreover, he treats his children badly. Therefore, giving custody of the children to their father is not beneficial at all to the children. The mother works in a nursery and receives (Part No. 21; Page No. 194) a salary. Also, her children go to the same nursery where she works. She has cared for them and provided them with their needs since she left the marital house. Dar Al-Ifta' asks for a clear Fatwa showing the period of custody as for both male and female children. Is it legal for the mother to raise the children instead of their father as she is more beneficial to them than their father who has not asked about them, seen them or participated in meeting their needs such as costs of living, clothes, medical treatment and education for more than a year and a half? Dar Al-Ifta' would like the Fatwa to be in accordance with the Madh-hab (School of Jurisprudence) set by Imam Ahmad ibn Hanbal (may Allah be Merciful to him) to be a fixed Fatwa by which Dar Al-Ifta' can be guided in the present time and in the future. Let us benefit by your knowledge. With my best regards.