Watford stabilised under new manager Javi Gracia to finish 14th in 2017/18. Allardyce, meanwhile, guided Everton to eighth but his six-month reign was underpinned by rising discontent from supporters at his sterile approach.

It was loveless relationship, ended with a reported £6m pay-off for the former England manager, and an episode now viewed by Everton fans as the football equivalent of having to briefly take some particularly toxic medicine to eventually feel only slightly better.

This is where Silva, finally, came in - and the ill-feeling bubbled to the surface once more.

The Premier League had been attempting to mediate in the case between the two clubs but a meeting in April 2018 failed to resolve the matter and when Silva was officially appointed at Everton at the end of the following month, Watford felt this confirmed their worst suspicions.

It did not stop the two clubs doing business when Brazil striker Richarlison left Watford to join Everton in the following July for a fee worth up to £50m - but suggestions the deal included a compensation package to settle the Silva dispute were soon dismissed.

It led to two acrimonious occasions, with some pantomime villainy from those in charge of Watford's record collection, when the two clubs met last season.

When Silva faced his old club for the first time at Goodison Park in December last year, a game which ended in a 2-2 draw, the travelling fans brandished plastic snakes and directed fierce verbal abuse in his direction.

The return at Vicarage Road in February was prefaced by Watford captain Troy Deeney, admittedly playing to the gallery at a fans' forum, saying they would "kick the s***" out of Everton. The comments were publicly noted by Silva.

Silva endured a miserable, hostile return. Not only were the snakes on show once more but Watford's choice of pre-match music raised some eyebrows at Everton, with those on the decks including Al Wilson's 1968 hit "The Snake", "Since U Been Gone" by Kelly Clarkson and "Go Your Own Way" by Fleetwood Mac.

Watford's 1-0 win was greeted with relish and they went on to prove how much they had moved on from Silva by reaching their first FA Cup Final since 1984, although it ended in a 6-0 humiliation at the hands of Manchester City.

Silva, meanwhile, oversaw some impressive performances towards the end of the season. Everton finished eighth but with none of the sourness that accompanied Allardyce's similar feat as Chelsea, Arsenal and Manchester United were all beaten by an increasingly attractive side that had Richarlison as its focal point.