AD 1000

1000 (M) was a leap year starting on Monday of the Julian calendar, the 1000th year of the Common Era (CE) and Anno Domini (AD) designations, the 1000th and last year of the 1st millennium, the 100th and last year of the 10th century, and the 1st year of the 1000s decade. As of the start of 1000, the Gregorian calendar was 5 days ahead of the Julian calendar, which was the dominant calendar of the time.

In the proleptic Gregorian calendar, it was a non-leap century year starting on Wednesday (like 1800).

The year falls well into the period of Old World history known as the Middle Ages; in Europe, it is sometimes and by convention considered the boundary date between the Early Middle Ages and the High Middle Ages. The Muslim world was in its Islamic Golden Age. China was in its Song dynasty, Korea was in its Goryeo dynasty, Vietnam was in its Anterior Lê dynasty and Japan was in its classical Heian period. India was divided into a number of lesser empires, such as the Eastern Chalukyas, Pala Empire (Kamboja Pala dynasty; Mahipala), Chola dynasty (Rajaraja I), Yadava dynasty, etc. Sub-Saharan Africa had developing urban centers and empires such as the Ghana Empire of the Wagadu, and the Trans-Saharan slave trade was beginning to be an important factor in the formation of the Sahelian kingdoms. The pre-ColumbianNew World was in a time of general transition in many regions. Wari and Tiwanaku cultures receded in power and influence while Chachapoya and Chimú cultures rose to prominence in South America. In Mesoamerica, the MayaTerminal Classic period saw the decline of many grand polities of the Petén like Palenque and Tikal yet a renewed vigor and greater construction phases of sites in the Yucatán Peninsula like Chichen Itza and Uxmal. Mitla, with Mixtec influence, became the more important site of the Zapotec, overshadowing the waning Monte Albán. Cholula flourished in central Mexico, as did Tula, the center of Toltec culture.

The World population is estimated to have been between c. 250 and 310 million.