Sir Christopher WREN was the designer of St. Paul's Cathedral in London, England. He was an English architect, astronomer, geometer, and mathematician who was born in 1632 and died in 1723. He is best known for his work on St. Paul's Cathedral, which was completed in 1710 and is considered one of the most significant works of English architecture. WREN also designed many other churches, including St. Stephen Walbrook, St. Bride's Fleet Street, and St. Clement Danes. He was knighted in 1673 and was a founding member of the Royal Society.