Although
Prussia had long owned territory in Westphalia, King Frederick William III had
preferred to incorporate the Kingdom of Saxony first. It was not until the Congress of Vienna in 1815 that the
Province of Westphalia came into being. The province was formed
from several different territories:
After the
end of World War II, the province was
merged with the northern half of the Rhine Province to form the
Germanstate of North Rhine-Westphalia in 1946, with the addition of the former state of
Lippe in 1947.