Ramadhan-ul
Mubarak

7th - Death of Hazrat Abu Talib(as)  (possible date)

10th - Death of Hazrat Khadija(as)

11th - Moakhat - Brotherhood between Muhajireen and Ansaar

13,14,15th - Ayyam-e-Bayz - the bright days

15th - Birth of Imam Hasan(as) - the 2nd Holy Imam - (3 AH)

17th - Victory at Battle of Badr - (2 AH)

19th- Evening - First probable night of Qadr - 

19th -Shab-e-Zarbat - Imam Ali(as) got injured in attack during prayers (40 AH)

21th- Shahadat of Imam Ali(as) - (40 AH)

23th - Third probable night of Shab-e-Qadr

Source - Azadari.com