After all the feisty banter going on in the discussion threads, I decided to go do some sleuthing on the acrimonious early history between Arsenal and Tottenham to see whether the various things said had merit. Let's dive in shall we?
(obviously this is based on what I could find on the internet. you can feel free to dispute my findings on those grounds)
Claim - "Arsenal stole Tottenham land"
True or False?
If by "land stealing" Spurs fans actually mean "catchment encroachment", then both true and false. Arsenal moved to Highbury, an area that Tottenham and Leyton Orient considered to be "theirs" in terms of attracting fans. But that in itself is the interesting part: When Arsenal moved in, Tottenham were not the only team that drew fans from that area. It wasn't "their land", so for them to claim that Arsenal encroached on it doesn't seem accurate. Most certainly no land was stolen - Arsenal paid to lease the site which from what I can gather was owned by the Church, not Tottenham, and the league approved the relocation despite objections from both Tottenham and Leyton Orient.
Claim - "Arsenal used illegal means to promote themselves to the first division at Tottenham's expense"
True or False?
Impossible to know. Spurs fans will claim it to be true but there is zero evidence to support that. Claims of foul play were alleged only.
The facts as we know them are that second-division Arsenal (6th place) argued for a spot in the newly expanded first division following World War I (2 more teams were to be added to the first division) on the basis that they had provided longstanding service to the league. This sparked several other second division teams to argue similarly for a first-division spot.
Tottenham, being a first-division relegation team that year, were caught up in the ensuing competition for the final spots. The league board had to vote on who to give first-division football to. Tottenham were expected to keep their spot despite their relegation position. (internet sources said that it was tradition for relegation teams to keep their spot if league play was ever interrupted. In this case that interruption was World War I)
However, the board chairman - who was a friend of Arsenal's owner - made a speech in support of Arsenal. In the end the overall board vote gave the final spot to Arsenal. The other spot had already been given to Chelsea (see: Manchester United/Liverpool matchfixing scandal), so there was no more room and Tottenham was relegated.
Spurs fans might have a point in that Arsenal did not really earn their promotion. On the other hand, here's an interesting tidbit from the North London Derby Wikipedia Page:
After an endorsement by League President and chairman of Liverpool John McKenna on account of their longer membership of the League, Arsenal won the vote by eighteen votes to Spurs' eight (Barnsley got five,Wolves four, Nottingham Forest three, Birmingham two and Hull City one) and were thus elected to the First Division. It has been frequently alleged that Arsenal chairman Sir Henry Norris used underhand dealings in order to bring this about, although nothing has been proven. The decision infuriated Tottenham and their supporters, although eleven years previously, Tottenham themselves had been elected to join the Football League Second Division despite only finishing 7th in the 1907-1908 Southern League, at the expense of Southern League champions Queen's Park Rangers, who had also applied and had resigned from the Southern League in expectation of promotion.
Pot, meet kettle?