Novak Djokovic and Serena Williams will begin Wimbledon, which gets under way on Monday, as favourites to retain their respective singles titles, yet much has changed for both players since their triumphs last year.

Djokovic arrived at SW19 12 months ago having suffered a third French Open final defeat in four years, his hopes of completing a career Grand Slam ended by an inspired Stan Wawrinka.

Remarkably, that loss remains the world number one's most recent grand-slam setback. Having finally tasted success at Roland Garros earlier this month, Djokovic holds all four major titles and is the first man to do so since the great Rod Laver in 1969.

Few would bet against another Serbian celebration when the men's singles final takes place at SW19 on July 10, but while Djokovic appears to be at the peak of his powers, Williams faces a challenge to re-assert her dominance in the women's game.

A second 'Serena Slam' was completed when Williams beat Garbine Muguruza at Wimbledon last year to secure possession of every slam crown.

However, shock reversals in New York, Melbourne and Paris - at the respective hands of Roberta Vinci, Angelique Kerber and Muguruza - have left Wimbledon as the only major honour in Williams' possession, the American still one short of Steffi Graf's Open Era record of 22 slams.

Nevertheless, it would take a brave person to bet against Williams over the coming fortnight, as she seeks a seventh Wimbledon title and fifth in eight years.

The 34-year-old's powerful game is ideally suited to grass, while the pain of her defeats in finals to Kerber and Muguruza will surely provide plentiful motivation.

Friday's draw saw Kerber, Simona Halep and Venus Williams join Muguruza in the opposite half of the draw to Serena, who will start her campaign against a qualifier.

Two-time Wimbledon winner Petra Kvitova and Agnieszka Radwanska - the beaten women's finalist four years ago - represent potential quarter-final and last-four opponents for the top seed, while Heather Watson could earn another shot at the champion in round three having come so close to causing an upset at the same stage in 2015.

Djokovic had to overcome world number two Andy Murray in the finals of the Australian Open and French Open, and it appears likely the two will meet again with a title on the line.

While Murray - now back with Ivan Lendl, the coach who guided him to Wimbledon glory in 2013 - has seen his last three slam finals end in agonising defeats to Djokovic, the Briton has arguably never enjoyed such superiority over the other players in the men's game.

With a 34-year-old Roger Federer having been hampered by injuries and Rafael Nadal absent due to a wrist problem, the big-serving Milos Raonic may fancy his chances of reaching the next level following his high-profile link-up with John McEnroe.

Raonic, a semi-finalist at SW19 in 2014, and Dominic Thiem, who beat Federer en route to a first grass-court title in Stuttgart earlier this month, will be many people's tips to disturb the established order in the men's singles.

Yet it is hard to look past another Djokovic-Murray final and it was the latter, of course, who prevailed the last time Centre Court played host to such a match.