1274

1274 (MCCLXXIV) was a common year starting on Monday of the Julian calendar, the 1274th year of the Common Era (CE) and Anno Domini (AD) designations, the 274th year of the 2nd millennium, the 74th year of the 13th century, and the 5th year of the 1270s decade. As of the start of 1274, the Gregorian calendar was 7 days ahead of the Julian calendar, which was the dominant calendar of the time.

• May 7 – The Second Council of Lyons, held by the leadership of the Roman Catholic Church convenes to consider the conquest of the Holy Land via Crusades and address the East-West Schism with the Byzantine church. The Council eventually approves a tithe to support efforts to conquer the Holy Land from Muslims, and reaches apparent resolution of the schism which ultimately proves unsuccessful.
• November – The diet at Nuremberg orders that all crown estates seized since the death of Frederick II, Holy Roman Emperor be restored to Rudolph I of Germany; almost all European rulers agree, with the notable exception of King Otakar II of Bohemia, who had benefited greatly by conquering or otherwise coming into possession of many of those lands.
• Pope Gregory X decrees that conclaves (meetings during which the electors have no contact with the outside) should be used for papal elections, reforming the electoral process which had taken over three years to elect him.