 When he was introduced in "School Hard" (season 2), Giles read that he was "barely two hundred," implying that he was either born or sired in 1797 or slightly earlier.In "The Initiative" (season 4) he said he was 126, thus born or sired in 1874.Flashbacks in "Fool for Love" (season 5) show that Spike was sired as an adult in 1880.