Until last year the Williams sisters ruled 21st century Wimbledon unopposed, their modern brand of women's power tennis crushing all before them.
The London Grand Slam's fast grass suited the Americans' uncompromising style. They could serve and volley opponents off the court.
The women's game has caught up since, however, and after Serena's shock defeat by then 17-year-old Russian Maria Sharapova in the 2004 final, a whole raft of upstarts fancy their chances against the sisters.
Venus Williams made her Wimbledon debut in 1997, having just turned 17, and won over the All England Club's traditionalists with her grace and enthusiasm on court, her disarming smile and her innovative choice of sportswear.
Beaded hair flying, the taller and slenderer of the Williams sisters covered the courts in giant steps, looking sharper and more athletic than any player before.
She won the title in 2000 and 2001, beating first Lindsay Davenport and then an emerging Justine Henin in the finals.
She then handed her mantle to Serena, 15 months her junior, losing to her sister in the 2002 and 2003 finals.
While Venus's star faded Serena shone and the younger sibling went on to win seven grand slam titles, the last in Australia in January, eclipsing her sister's four.
WRONG CALL
Venus appeared to have lost some of her hunger and went down in the second round last year to Croatian Karolina Sprem in a controversial match marred by a wrong call from the umpire.
Though a lowly 16th in the rankings now and seeded 14 at next week's championships, Venus has shown sparks of renewed enthusiasm this season, however, beating her sister for the first time in more than three years in Miami in March then winning her first tournament for a year in Istanbul last month.
An insipid 6-3, 1-6, 6-1 defeat by Bulgarian 15-year-old Sesil Karatancheva at the French Open rather took the shine off that success. "I beat myself," Venus said. "I wanted to keep playing the aggressive game but I just maybe went for too much, basically there were just too many errors."
The sisters have suffered family trauma over the last two years with the murder of an older sister and the break-up of their parents' marriage
They have also suffered injuries. Serena had a long layoff and knee surgery after her Wimbledon triumph in 2003 but looked resurgent this year, with her first grand slam win in 18 months in Melbourne.
She was going well until she twisted her ankle at Amelia Island in April which forced her out of most of the claycourt season including Roland Garros so she is short of match practice.
The pair have stuck to their Wimbledon warm-up routine, however, avoiding competition and practising in peace. Serena said match toughness would not be a problem.
"I've been playing a long time and I know what I need to do to win," she said in a telephone conference on Thursday.
"I'm here. I'm healthy and I'll do the best I can. I feel good and if I'm not ready now then more than likely I'll never be ready."
SAME QUARTER
The sisters are in the same quarter of the draw for the tournament, which starts on Monday, and could face each other in the fourth round.
Serena, seeded four, meets 103rd ranked compatriot Angela Haynes in what should prove a gentle first-round workout.
Venus is up against a qualifier, but her opponent will have the advantage of having earned her grass legs after going several rounds on the lawns in nearby Roehampton.
Venus may be comforted to learn that Sprem is in the other half of the draw.
If all goes to plan Serena will meet last year's nemesis Sharapova, seeded two, in the semi-finals but only if she can overcome French Open champion Henin-Hardenne in the quarter-finals.
The Russian and the Belgian will be anxious to prove that last year was not a blip but signalled an end to the Williams Wimbledon hegemony.
Serena said she had been making some changes to her game, working on aspects she could improve and knuckling down hard. Her aim is a third title.
"It would definitely be awesome," she said. "I see myself doing it."
