Dutch East India Trading Co.
Most Valuable company ever in inflation adjusted dollars. Those that have read James Clavell, or the Baroque cycle or other period books will know this company. You will know it if you know your 17th Century history.
Originally a Spice trader it was the first publically traded company on the first publicly traded Stock market. Valued in todays dollars? – 7.4 Trillion. With a T.
They even had their own private army.