Mark Robson was understandably a little nervous as he boarded the flight home from Madrid.

Sir Bobby Robson's son had a precious piece of hand luggage he needed to get back in one piece - a Ballon d'Or world coach of the year award.

The gong was donated by Jose Mourinho for a charity auction in the name of his late mentor in 2011.

It went on to help raise £26,000 for the Sir Bobby Robson Foundation, which aims to find more effective ways to detect and treat cancer.

And the family have never forgotten the gesture.

"It was incredibly thoughtful of Jose to do that," Mark said. "It shows you what he is like deep down."

It also illustrates the lasting affection Mourinho has for Sir Bobby, who he shadowed as an interpreter and assistant for five years in the 1990s, as the Portuguese prepares to take his Benfica side to St James' Park.

Make no mistake, Mourinho will be desperate to record just his fourth win on Tyneside when his team face Newcastle United in the Champions League on Tuesday night.

But this will still be an occasion laced with emotion as he returns to "Mr Robson's home" and makes his way past the bust of the former Newcastle manager in the players' entrance.

So how was this close bond forged?

This was a time long before the 'Special One' moniker.

In fact, it was Sir Bobby, rather than Mourinho, who was mobbed as he made his way through arrivals in 1992.

The former England manager had just touched down in Lisbon to take charge of Sporting and club president Sousa Cintra was there to greet him.

However, the Portuguese did not speak English so he brought polyglot Mourinho along.

Mourinho had been recommended by Sporting assistant Manuel Fernandes, who had previously worked with the budding coach at Vitoria de Setubal and Estrela da Amadora.

It was a moment that changed the course of Mourinho's life.

Mourinho stood alongside Sir Bobby on the training ground. He helped get his message across to the players and in the media and even accompanied him in meetings with the hierarchy.

The pair were thrown together, with a 30-year age gap, but it was quickly apparent to Sporting defender Stan Valckx that they made a "good couple".

"During the team talk before the game, Bobby spoke for a few minutes to explain something and, then, Mourinho translated it into Portuguese," he said. "It took 10 minutes with many emotions in what he was saying.

"It was obvious that he was much more than an interpreter. He was very loyal and very ambitious. He was a big help for Bobby.

"Sometimes he did exercises on the pitch and videos like what an assistant coach does. In those years, 90% of the Portuguese players didn't speak English so there was a lot of work. Mourinho was very busy. Let's say it like that."

It was through Mourinho that Sir Bobby would later learn he had been sacked.

Sporting may have been top of the league in December 1993, but Cintra grabbed the intercom to make a dramatic announcement on the team flight back from Austria.

The club president announced in his native tongue that Sir Bobby would be dismissed following his side's elimination from the Uefa Cup at the hands of Casino Salzburg.

Yet it was not the end of Sir Bobby and Mourinho's partnership.

Sir Bobby consulted Mourinho when he was offered the Porto job a year or so later and, tellingly, took his assistant with him.

"If something was said behind dad's back, Jose was watching," Mark Robson said.

"He was his eyes and ears, and a sounding board. You need a right-hand [man] in those environments and [Mourinho] was that man.

"Because he was such a strong character - even at that age - he could handle it and do it quietly and efficiently.

"If there were any disruptors, Jose would spot them and dad could deal with it. It obviously worked well - the proof is in the pudding."

Sir Bobby went on to win five trophies at Porto, including two league titles, before Barcelona came calling in 1996.

And there was one particular member of staff he was determined to take with him.

Those at the top at Barcelona initially wanted someone with club connections to be Sir Bobby's assistant, but he insisted it had to be Mourinho.

For good reason.

Sir Bobby was walking into a divided club following the departure of legendary manager Johan Cruyff and needed someone he trusted implicitly, who could help get his message across in another foreign language.

By this stage, Mourinho's role had long since evolved.

He helped out on the training ground. He produced scouting dossiers on the opposition that Sir Bobby rated as the best he had ever seen. Crucially, he was used to dealing with international players.

In a testing environment, the pair complemented each other once again as midfielder Guillermo Amor explained.

"They managed to create a good atmosphere and make a very strong team," he said.

"Jose had more contact with the players due to his fluency in the language and his age, which was very similar to ours.

"He had great respect for Bobby and Bobby had great faith in everything Jose could do on the field and in the locker room."

Sir Bobby went on to win the European Cup Winners' Cup, the Copa Del Rey and the Spanish Cup in what proved to be his final season with Mourinho before the Barcelona manager was moved upstairs to the position of general manager and replaced by Louis van Gaal.

Mourinho told Sir Bobby he wanted to leave out of loyalty but his mentor convinced him to stay, having already briefed van Gaal about the merits of keeping his assistant.

Had Mourinho not spent three further three years at the Nou Camp under van Gaal, the Portuguese could well have followed Sir Bobby to Newcastle in 1999.

Instead he went it alone - but Sir Bobby's influence lives on.

To this day, Mourinho cherishes those moments the pair's families shared in Sitges, the meals Sir Bobby never let him pay for and the lessons he taught him about life.

It is why the 62-year-old considers himself a "little Magpie".

"The club up there know how much love and respect I have for them," he told CBS earlier this month. "I learned that love from Mr Robson."