Arms were originally granted to the London Borough by letters patent dated 1 October 1965.

[5] Originally, the intention was that the borough would receive the royal epithet on 3 January, but this was postponed by one month to 3 February.

The two six-pointed radiated stars from the old arms were replaced by two five-pointed mullets, one hour glass became two and instead of three cannon barrels with a lion's head on each, there is now only one.

The same is true for the Tudor rose in the crest, which also is marking the borough's long association with royalty.

The symbols relate to the Royal Observatory, built in 1675 for the advancement of navigation and nautical astronomy.