1633 is an alternate history novel co-written by American authors Eric Flint and David Weber published in 2002, and sequel to 1632 in the 1632 series. 1633 is the second major novel in the series and together with the anthology Ring of Fire, the two sequels begin the series hallmarks of being a shared universe with collaborative writing being very common, as well as one—far more unusual— which mixes many canonical anthologies with its works of novel length. Wikipedia