Sired Circle
The Master sired Darla in the year 1609 in Virginia were she was dying from a deadly sickness.
Then Darla met Liam (Angel's human name) on 1753 in Galway, Ireland were he was just a worthless drunk.
Later Darla and Angelus sire Drusilla on 1860 in London where she was an innocent Woman.
Twenty years later, Drusilla meets Spike in 1880 in London where she sires him and he is no longer the "horrible" poet he was before being sired.
In Season 3 of Buffy the episode :Graduation Day Part II a random vampire sires Harmony.
Later Darla is killed by Angel, but brought back to life by Wolfram and Hart where she is sired by Drusilla.
The Master --> Darla --> Angel --> Drusilla --> Spike
random vampire-->Harmony
Drusilla --> Darla
