Greek mathematician; worked c. 320 AD (Alexandria)
Pappus was the last great Greek mathematician to move geometry forward. He wrote the Synagoge ("Collection"), an encyclopaedia of eight books that summarized geometry up to his days. The material collected over centuries was reorganized and theorems and proofs reformulated. The entire work, although substantial, was intended to be read in conjunction with the originals (which would all have been in Alexandria's Library at the time).
The surviving parts of the first and second book of the Synagoge deal with algebra. Books 3 - 7 cover all areas of geometry, book 8 addresses problems of mechanics. The geometry of projections is based on one of Pappus' theorems.
Other works include commentaries on the writings of Ptolemy and Euclid.