If you still believe that Santa Claus will be sliding down your chimney on Christmas Eve, skip Jeremy Seal's historical travelogue Santa: A Life. Not that Seal is a killjoy. After all, for a start the British writer indulgently ferries his wonderstruck daughters to Santa's Kingdom, a vast, tawdry grotto in Birmingham, England, and then, a year later, all the way to Lapland. In between, though, Seal comes to admire Santa's prototype, as he tracks the shape-shifting Byzantine bishop St. Nicholas across 17 centuries of Christendom. Born in Christian Myra (now Demre) in southern Turkey in 280 A.D., Nick was sainted for anonymous gift giving to needy folk, and nominated a guardian of seafarers. After his bones were removed by Italian raiders to the port of Bari in 1087, prisoners, prostitutes, pawnbrokers and others flocked to his patronage. Soon, every Christian city wanted a piece of him, and relic hunters provided fingers, hair and teeth upon which to build churches. Reaching Amsterdam around 1300, he eventually became a supplier of goodies to kids, as shown in the 1907 postcard at left. And it was Dutch pilgrims who took him to America, where, in 19th century New York City, frothy writers and advertisers turned the austere bishop into the fat, jolly, pipe-smoking Santa Claus. Believe in him or not, Santa has more than earned his place in Yuletide history.