There are many regional proxies from around the world that do show the existence of a warm period (warmer than today in most places) called the "Medieval Warm Period" or "Medieval Climate Optimum" roughly from 900-1350AD and a "Little Ice Age" roughly from c.1450 to 1850AD.
Amongst the strongest evidence of this is a study done by Dr Lloyd Keigwin of Woods Hole Oceanographic Institute in 1996. The study was done in the Sargasso Sea near Bermuda, and involved an area of sea bed which had a very high rate of sedimentation (paleoclimatologists like such areas because they can produce high resolution sedimentary information) and a particular species of plankton called Globigerinoides ruber.
G. ruber has the interesting property that it "lives year-round at the surface of the Sargasso Sea, and it happens to deposit its calcium carbonate close to oxygen isotopic equilibrium with seawater. This means that G. ruber is ideal for reconstructing past changes in the temperature and salinity of Sargasso Sea surface waters"
This leads to a direct temperature record of the surface of the Sargasso Sea for the last 3000 years in high resolution form. Because it deposits its calcium carbonate close to the oxygen isotopic equilibrium and that this equilibrium is temperature-sensitive, such a record can have an actual temperature assigned to it to good accuracy, as the figure below illustrates:
Note that not only can the Medieval Warm Period be seen, around 1000 years ago and the depths of the Little Ice Age around 500 years ago, but also the Dark Ages cold period (1700 years BP) and the Roman Warm period (around 2000 years BP) and other warm periods at 2500 and 3000 years BP.
An overview article of this study was published in Oceanus and can be found here. If you want a copy of the technical report sent to Science then e-mail me via climateaudit AT gmail.com and I’ll send you a copy.