1236 (MCCXXXVI) was a leap year starting on Tuesday of the Julian calendar, the 1236th year of the Common Era (CE) and Anno Domini (AD) designations, the 236th year of the 2nd millennium, the 36th year of the 13th century, and the 7th year of the 1230s decade. As of the start of 1236, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.