It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) married her three years, or about that, before he departed from Makkah, and at that time she was six years old. Then after he arrived in Madinah he consummated the marriage with her, and on the day of its consummation she was nine years old.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19356