After a rebellious college life, Giles finally accepts his destiny to be a watcher like his father and grandmother before him. The Watchers Council eventually send him to Sunnydale as High School librarian and he arrives there shortly before Buffy herself.
Giles spends most of his time bemused by teenage girls, technology and Americans. Over time though he grows to love Buffy as a daughter and even goes against The Watchers Council on her behalf, resulting in him being sacked. Giles is the one with the books and the ability to find himself in the wrong place (usually with the wrong object) at the wrong time.
Beneath the tweed suit, however, lies a hidden rebel named Ripper with a slightly shady demon worshipping past.
Giles finds love with techno pagan Jenny Calendar only to have her taken from him by Buffy's blood sucking boyfriend, Angel. After a brief encounter with Joyce, Giles finally seems to have found long distance love with Olivia.
After the Buffy blows the school (and Giles' library) up, in order to kill the mayor-snake demon, Giles is unemployed for a while which gives him a chance to catch up with his guitar playing. Feeling at a loose end he so takes up the dangerous occupation of running the magic shop. When the watcher's council return to Sunnydale on the pretext of having information about Glory, Buffy makes them reinstate him as watcher.
When his slayer dies to save the world, Giles finds there is nothing left for him in Sunnydale, and handing over the running of The Magic Box to his assistant, Anya, he leaves for England, only to get the next plane back when he hears that Willow has brought Buffy back. He soon realises that Buffy is leaning on him too heavily and not standing on her own two feet and leaves for England again.
Back in England, he hears of Willow’s lust for vengeance, and with the help of a powerful Wiccan group returns to Sunnydale fully loaded with magical power to try and stop Willow. He nearly dies in the process and in the end it is only Xander’s love that can stop Willow.
On his return to England, Giles takes Willow with him and introduces her to the Wicca group who teach her to control her power.
When he hears of the destruction of the Watcher’s Council and that the potential Slayer’s are being picked off one by one, he gathers those that he can and takes them to Sunnydale. Here he continues to seek out potential Slayers and bring them to Buffy’s ever growing household.
Although he managed to get on Buffy’s bad side by sending the newly-ensouled Spike on a mission that nearly kills him, Giles makes it through the final apocalypse with honour.
