A lot of us wouldn't fit in in the "old days".  The technical term for marrying "too" closely is consanguinity.  You can find more about the laws over time at: http://www.genuki.org.uk/big/eng/LIN/consanguinity.html     Lou -snip- Hello Folks, Horrified at finding a notable first-cousin marriage in Wirksworth in 1872, -snip-