855
| Years: 851 852 853 854 - 855 - 856 857 858 859 | |
| Decades: 820s 830s 840s - 850s - 860s 870s 880s | |
| Centuries: 8th century - 9th century - 10th century | |
Events
- Louis II succeeds Lothair as western emperor. Two other sons, Lothair and Charles, also get parts of the kingdom.
- Succession of Pope Benedict III (855 - 858). Anastius is made anti-pope by Lothair.
- Ethelwulf, king of Wessex and Bretwalda, abdicates in favor of his son Ethelbald.
- Ethelwulf grants the English churches the right to receive tithes.
- Edmund becomes king of East Anglia.
Deaths
- Lothair, western emperor
- Pope Leo IV (847 - 855)