It is narrated from Anas (may Allah be pleased with him) who states that the Prophet (peace be upon him), Abu Bakr, Umar, and Uthman (may Allah be pleased with them) used to begin the recitation with "Alhamdu lillahi Rabbil 'alamin."
Hadith Referenceمسند الإمام الشافعي / كتاب الصلاة / 209
Hadith Takhrijأخرجہ مسلم، الصلاۃ، باب حجۃ من قال لا یجہر بالبسملۃ: 399۔