The day Manchester United legend Sir Bobby Charlton wore the blue of Man City

Some players transcend football rivalries. Sir Bobby Charlton was one of them.

Tributes to the Manchester United legend will continue this weekend when Manchester City travel to Old Trafford for the first derby of the season. In paying tribute to Sir Bobby last weekend, Pep Guardiola promised that City would play their part in remembering a true great of English - and international - football. England international John Stones promised the same.

When City line up to remember the ultimate hero of every United fan, they may remember one night in 1979 that summed up the kind of man Sir Bobby was. It was a night when he donned the Sky Blue of City and old grievances were put to bed, in a side made up of both United and City legends, for Colin Bell's testimonial.

While Charlton was winning the World Cup with England in 1966, Bell was part of the generation tasked with emulating the greatest generation this country has ever seen. Bell was earmarked as Charlton's successor for England, often suffering by playing in Charlton's shadow for the Three Lions. When Alf Ramsey wanted Charlton to rest at the 1970 World Cup, he brought on Bell for the United man in the quarter-final with England leading 2-1. West Germany would go on to win 3-2, with Bell made something of a scapegoat, seemingly just for not being Bobby Charlton.

Back in Manchester, though, the pair shared many similarities while they remained rivals of sorts for club and country. Both remain the greatest players to wear the shirt of their respective clubs, both are one-third of a 'holy trinity', and both have been recognised with a stand named after them. When City unveil a statue of Bell, Mike Summerbee and Franny Lee, it will match United's statue at Old Trafford of