The Williams sisters legacy will live on forever
While becoming the most successful sibling act in the history of sport, Venus and Serena Williams have also made women's tennis faster, quicker, harder-hitting and more athletic, and inspired generations of youngsters to play the game.
Author Cecil Harris explains their phenomenal impact...
The Williams sisters, who learned to play on rough-hewn courts in the hardscrabble Compton section of Southern California, used to be ranked No 1 and No 2 in the world.
If you took that for granted at the time, then that's unfortunate because we are not likely to see another tennis family achieve that again.
Serena and Venus have combined for 30 Grand Slam titles in singles and 14 more in doubles.
They have also won the last three Olympic gold medals in doubles. Add to that, Olympic gold in singles for Venus in 2000 and Serena in 2012 and you have the stuff of which legends are made.
Each sister turned pro in the 1990s at age 14.
They were strong and confident with beads in their braided hair, crushing serves, forehands and two-fisted backhands while sending a message to their rivals:
Get stronger and fitter or get out of the way.
The Williams Sisters, their legacy will live on forever for what they have achieved on an off the court.
Enormous credit must go to their parents, Richard Williams and Oracene Price. Also deserving of credit is an athlete who blazed a trail for the sisters: Althea Gibson.
In 1957, Gibson became the first black player ever ranked world No 1.
"I once wrote a paper about her for school," Serena said. "There were tournaments that wouldn't let her play because they weren't accepting blacks.
And when she could get into tournaments, she wasn't always allowed to use the locker room like the other players or eat in the dining room like the others.
She had to sleep in cars in some tournaments when everybody else was sleeping in hotels."
Serena collected her first major back in 1999, winning the US Open
Serena's 1999 US Open title was the first by a black woman at a major since Gibson won the 1958 US Nationals (forerunner of the US Open).
Before Gibson won consecutive singles crowns at Wimbledon and the US Nationals in 1957 and 1958, she won the 1956 Wimbledon ladies' doubles title with Angela Buxton, the British-born daughter of Russian Jews.
Buxton, who faced anti-Semitism, and Gibson, who faced racism, became lifelong friends.
Nevertheless, a Wimbledon triumph by the two tennis outsiders did not garner much media attention.
"When we won the doubles title," Buxton said, "there was in one of our major papers in England a small column in thin type, 'Minorities Win.' That was it."
Drawing upon inspiration from her elder sister Venus and from Gibson, Serena has become the gold standard bearer in women's tennis with a record 23 major titles in the Open era (since 1968).
She has used her incomparable serve, power game, athleticism and intensity to win Wimbledon championships in 2002, 2003, 2009, 2010, 2012, 2015 and 2016.
As for Venus, the record book shows that she has conquered Wimbledon in 2000, 2001, 2005, 2007 and 2008.
However, her most dynamic victory at the All England Lawn Tennis and Croquet Club happened off the court, the culmination of a three-year battle that began in 2005 to achieve pay equity for women at the sport's premier tournament.
Venus' last Grand Slam title came in 2008 at Wimbledon
The US Open was the first Grand Slam event to offer equal prize money in 1973.
Eventually, the French Open and the Australian Open followed suit. However, the men who ran Wimbledon believed that since men played best-of-five-set matches at the majors while women played best-of-three, men had to work longer for the money and should be paid more.
But women's tennis, certainly by 2005, had proven itself to be as big a draw as men's tennis.
Indeed, the emergence of Serena and Venus as global superstars made the sisters as much of a drawing card as any leading man.
In 2005, Venus advocated for gender equity at the annual meeting of the Grand Slam committee, held during the second Friday at Wimbledon.
The committee consists of representatives from the four Grand Slam events plus the Women's Tennis Association and the Association of Tennis Professionals (men's tour).
In a room full of men with decision-making power, Venus said, "Close your eyes. No peeking. Now, I would like you to imagine being a young girl growing up with dreams of being an athlete, a scientist, an artist, president of the United States.
And then, one day, somebody tells you that you can't be that, you can't reach the same level as a boy who has worked as hard as you, done as well as you.
You're told that there's a limit. There's a limit to what you can achieve because of your gender."
The day after stating her case to the committee, Venus scored a dramatic victory over Lindsay Davenport in the Wimbledon final, 4-6 7-6 (7-4) 9-7 in two hours and 45 minutes - the longest ladies' final in Wimbledon history and, arguably, the finest.
Yet the All England Club voted against bringing pay equity to Wimbledon in 2006. Instead, a modest pay increase was made to the women's purse. Men continued to be paid more across the board, but the female champion would make "only" £30,000 less than the male champion.
The difference in pay would be so modest now as to seem spiteful.
With hearty support from Serena and other female players, Venus served as the anchorwoman in the ongoing battle for gender equality.
Former Prime Minister Tony Blair endorsed the idea of pay equality at Wimbledon
The WTA secured the backing of prominent female political figures in the UK such as Tessa Jowell, secretary of state for culture, media and sport, and health secretary, Patricia Hewitt.
Venus also gained the support of the United Nations Educational, Scientific and Cultural Organisation (UNESCO).
Venus then wrote an editorial that appeared in The Times of London on June 26, 2006, one that effectively put the Wimbledon patriarchs on the defensive:
"It is a shame that the greatest tournament in tennis, which should be a positive symbol for the sport, has been tarnished," she wrote. "How can it be that Wimbledon finds itself on the wrong side of history?"
Once Venus's editorial appeared, the issue of pay equity became a hot topic in UK workplaces, homes, neighbourhoods, even in Parliament.
When Janet Anderson, MP for Rossendale and Darwen, asked British leader Tony Blair during Prime Minister's questions about the need for pay equity at Wimbledon, Blair endorsed the idea.
Game, set and match.
Pay equity has been the rule at Wimbledon ever since. With Venus tapping into her power and using her voice to amplify and persuade, women in sport achieved a major victory.
The impact of Venus and Serena Williams extends well beyond their brilliance on a tennis court.
They play now in the twilight of their years; Venus turns 40 in June, Serena 39 in September.
Yet they are cultural icons and role models for girls and young women, boys and young men, throughout the world.