According to the BBC, the Thames River last froze over completely in 1814. A five-day "Frost Fair" was held in its honor beginning on Feb. 1 , 1814. Other partial freezes have occurred since, the last and most notable being "The Big Freeze of 1963."
During the "Frost Fair" in 1814, oxen were grilled, drinks were consumed, dancing ensued and an elephant marched aside Blackfriars Bridge across the frozen Thames River. The river froze over at least 23 times from 1309 to 1814. The river was frozen solid enough to hold a "Frost Fair" five times, counting the one in 1814. When the Thames River froze over, this affected the livelihood of the watermen and lightermen who moved people and goods. To compensate for lost earnings, they organized the fairs, charging the renters and traders for ice access.