I've linked to Prokudin-Gorskii before but this piece by Ctein is an appreciation of his remarkable achievement and with links to some great photographs.

In Praise of Prokudin-Gorskii

In my always-humble opinion, Sergei Mikhailovich Prokudin-Gorskii (1863-1944) was the first master of modern color photography.

Head study
Between 1905 and 1915