This morning my chum, writer and songstress Ariane Sherine, Tweeted about the oddity of London postcodes.
There are SW (south west) postcodes, SE (south east), postcodes, NW (north west) ones but no NE one for north east London. That is because NE is the postcode for Newcastle.
Likewise, there are N, E and W London postcodes (north, east and west) but no S postcode, because that is used for Sheffield.
Another quirk, designed to confuse the unwary, is that the numbering of London postcodes is alphabetical, not geographical. So a postcode area 3 is not necessarily next to 2 and 4…
However, I am more interested in sex.
So, we have or had Middlesex (the central area), Wessex (ie West Sex), Sussex (South Sex), Essex (East Sex) but no North Sex, presumably because the people of Nosex eventually died out.
Apparently, in this context, ‘sex’ turns out to be an abbreviation and corruption of ‘Saxon’, which is a disappointment.
But life is full of disappointments.
I am going to have breakfast now.
SO IT GOES - John Fleming's blog 
The writer clearly doesn’t know the subject, because London was the first city to be divided into districts (EC, WC, N, NE, E, SE, S, SW, W, and NW) in the nineteenth century. Later in the 1800s the NE and S districts were abolished. Postcodes only came in during the 1960s, by which time NE and S were available and used for Newcastle and Sheffield respectively!
Fair enough. Though, to be equally fair, the piece only talks about postcodes not districts…
Postcodes were born out of the former districts, which is why most of the original London districts have been incorporated into what are now known as postcodes. The two subjects cannot be separated and neither can their related history be ignored.
I bow to your logic with shamefaced contrition.