Some recent climate history:
600-200 BC: Unnamed cold period that preceded the Roman Warming.
200 BC-AD 600: Roman Warming.
600-900: Dark Ages cold period.
900-1300: Medieval Warming or Little Climate Optimum.
1300-1850: Little Ice Age (two-stage)
Modern Climate History:
1850-1940: Warming, especially between 1920-1940.
1940-1975: Cooling trend.
1976-1978: Sudden warming spurt.
1979-present: A large disparity between surface thermometers, which show a fairly strong warming, and the independent temperature readings of satellites and balloons, which show little warming trend.
Recent research shows that this approximate 1,500 year cycle goes back at least a million years, layered over top of the glacial periods and inter-glacial optimums.