The 800s decade ran from January 1, 800, to December 31, 809.
The 810s decade ran from January 1, 810, to December 31, 819.
The 820s decade ran from January 1, 820, to December 31, 829.
The 830s decade ran from January 1, 830, to December 31, 839.
The 840s decade ran from January 1, 840, to December 31, 849.
The 780s decade ran from January 1, 780, to December 31, 789.
The 760s decade ran from January 1, 760, to December 31, 769.
The 710s decade ran from January 1, 710, to December 31, 719.
Year 742 (DCCXLII) was a common year starting on Monday of the Julian calendar, the 742nd year of the Common Era (CE) and Anno Domini (AD) designations, the 742nd year of the 1st millennium, the 42nd year of the 8th century, and the 3rd year of the 740s decade. The denomination 742 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 840 (DCCCXL) was a leap year starting on Thursday in the Julian calendar, the 840th year of the Common Era (CE) and Anno Domini (AD) designations, the 840th year of the 1st millennium, the 40th year of the 9th century, and the 1st year of the 840s decade.
Year 842 (DCCCXLII) was a common year starting on Sunday of the Julian calendar, the 842nd year of the Common Era (CE) and Anno Domini (AD) designations, the 842nd year of the 1st millennium, the 42nd year of the 9th century, and the 3rd year of the 840s decade.
The 680s decade ran from January 1, 680, to December 31, 689.
Year 827 (DCCCXXVII) was a common year starting on Tuesday of the Julian calendar.
Year 807 (DCCCVII) was a common year starting on Friday of the Julian calendar, the 807th year of the Common Era (CE) and Anno Domini (AD) designations, the 807th year of the 1st millennium, the 7th year of the 9th century, and the 8th year of the 800s decade.
Year 806 (DCCCVI) was a common year starting on Thursday of the Julian calendar, the 806th year of the Common Era (CE) and Anno Domini (AD) designations, the 806th year of the 1st millennium, the 6th year of the 9th century, and the 7th year of the 800s decade.
Year 789 (DCCLXXXIX) was a common year starting on Thursday of the Julian calendar. The denomination 789 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
Year 820 (DCCCXX) was a leap year starting on Sunday of the Julian calendar.
Year 833 (DCCCXXXIII) was a common year starting on Wednesday of the Julian calendar.
Year 873 (DCCCLXXIII) was a common year starting on Thursday of the Julian calendar.
Year 904 (CMIV) was a leap year starting on Sunday of the Julian calendar.
