1866 (MDCCCLXVI) was a common year starting on Monday (dominical letter G) of the Gregorian calendar and a common year starting on Saturday (dominical letter B) of the Julian calendar, the 1866th year of the Common Era (CE) and Anno Domini (AD) designations, the 866th year of the 2nd millennium, the 66th year of the 19th century, and the seventh year of the 1860s decade. As of the start of 1866, the Gregorian calendar was 12 days ahead of the Julian calendar, which remained in localised use until 1918.

Events

January–March

April–June

July–September

October–December

Date unknown

Births

January–March

April–June

July–September

October–December

Deaths

January–June

July–December

Date unknown