This is the <a href="https://en.wikipedia.org/wiki/White_Ensign" class="extiw" title="w:White Ensign">White Ensign</a> used by the <a href="https://en.wikipedia.org/wiki/Royal_Navy" class="extiw" title="w:Royal Navy">Royal Navy</a> of the <a href="https://en.wikipedia.org/wiki/Kingdom_of_Great_Britain" class="extiw" title="w:Kingdom of Great Britain">Kingdom of Great Britain</a> from 1707 until 1800. Updated version, more accurate.
Paul Dobson (<a href="https://en.wikipedia.org/wiki/User:Martocticvs" class="extiw" title="en:User:Martocticvs">Martocticvs</a>)
2006-10-09
<span class="int-own-work" lang="en">Own work</span>