Which flag is this?

The East India Company was the name of an extraordinary private enterprise that established English -- and later British -- interests in India.

The Company was chartered as the "Governor and Company of Merchants of London Trading into the East-Indies". It rose to account for half of the world's trade during the mid-1700s and early 1800s, particularly in basic commodities. The Company also ruled the beginnings of the British Empire in India.

Both the name and the flag of the Company changed as Britain's political organisation changed: with the Acts of Union 1707 England and Scotland formed the Kingdom of Great Britain; with the Acts of Union 1800 Great Britain and Ireland formed the United Kingdom of Great Britain and Ireland; with each of these steps the flag of the "mother country" changed and, with it, the flag of the Company. The version depicted in the question is from 1801.

The flag of Hawaii bears a superficial resemblance to this, but the stripes alternate white, red and blue.