Union Jack(ed)

London Metropolitan Archives' FLickr photostream has some interesting images (mostly 19th and 20th cent.). Dirck Stoop's "The Manner how her Maties. D. Catherine imbarketh from Lisbon for England," (which they title, The Marriage of Catherine of Braganza to King Charles II, 1662) has the English Fleet flying the Union Jack, which must be one of the earliest portrayals of said flag.  The OED, has the following early reference - London Gazette, 924 (1674), "[t]hat from henceforth [subjects] do not presume to wear His Majesties Jack (commonly called, The Union Jack) in any of their Ships or Vessels, without particular Warrant" - although the practice dates from the early Stuarts.