Saturday in Dublin cousin will go head to head against cousin. There are many cases of sibling rivalry.
This Saturday in Dublin cousin will go head to head against cousin - Richardt Strauss at hooker for Ireland against Adriaan Strauss of South Africa, cousins, Old Greys, Free Staters and opponents where heads do really meet, when they're hooking cheek to cheek.
It is not unusual for relatives to play for different countries.
We have even cases of brothers playing for different countries, a father-and-son split and twins against each other. And it goes a long way back.
The first pair of brothers to win caps for different countries were the Fagans, George and Arthur. In 1878, Ireland played England at Lansdowne Road, the first time that the oldest, still-extant Test ground was used for a Test, just the fourth time the two countries had met.
Minutes before kick-off Gus Whitestone, an Irish threequarter, withdrew and George Fagan, a 19-year-old pupil at Kingstown School was drafted into play in his stead. George died in 1885 but in 1887 Arthur, George's younger brother Arthur, a medical student at Guy's, played at fullback for England against Ireland at Lansdowne Road. When George played for Ireland, England won; when Arthur played for England, Ireland won. They were the only Tests the brothers played.
There have been other instances down the years.
In 1884 Frank Hancock of Cardiff played for Wales, as he did four times. In fact he captained Wales. In 1886 his brother Baby Hancock, a huge forward whose names were Philip Froude, played for England, as he did three times. He also toured South Africa in 1891 and 1896. They did not play against each other. Frank was a back who is believed to have introduced the four-threequarter system.
The first time it concerned South Africa was in the 19th century. In 1891, big centre RL Aston was the star of the tour, scoring 30 tries in 19 matches, which is still a record. When the next touring team came, in 1896, RL's brother Ferdie (real names Fitzmaurice Thomas Drake) played for South Africa, captained South Africa in one Test in fact.
Dugald Macdonald played for South Africa in 1974, younger brother Donald for Scotland in 1977 and 1978.
Matt Cockbain played 63 times for Australia between 1997 and 2003, playing in two World Cup Finals. Brent Cockbain played 24 times for Wales between 2003 and 2007.
Scrumhalf Dimitri Yachvili played for France; his brother, flank Grégoire Yachvili, played for Georgia but they did not play against each other. Their father Michel played for France but grandfather escaped Georgia and joined the French resistance during the war. His Georgia-ness enabled Grégoire to play for Georgia.
The Lunds did not play against each other because England has never played Norway. Magnus played for England, bearded Erik for Norway.
The Tuilagis also did not play against each other, extended as their family is. Brothers Henry, Freddie, Alesana, Anitelea and Sanele Vavae all played for Samoa but Manu, born in Samoa 15 years after Henry, plays for England.
But the Umagas played against each other - Tana for New Zealand and Mike for Samoa.
The All Blacks won that match 71-13. Tana captained the All Blacks. Both brothers were born in Lower Hutt, New Zealand.
Brad and Dylan Mika were both born in Auckland and both became All Blacks, though Dylan also played for Samoa. He then stood down for three years so that, in accordance with the eligibility regulations of the time, he could play for New Zealand.
That is as nothing compared with the multinational Bachops, Stephen and Graeme, who actually played against each other in the 1999 Rugby World Cup.
In those days of elastic eligibility regulations, they danced about. Stephen played for Samoa, then New Zealand and then Samoa again. Graeme played for New Zealand and then Japan. In 1999, in Wrexham, Graeme played scrumhalf for Japan, Stephen flyhalf for Samoa. They repeated the dose later in the year.
There are also a father whose sons played for another country countries. Bryan, the great New Zealand wing called BG, played for New Zealand, but his sons - Gavin and Paul - played for Samoa. All three were born in Auckland, but BG's father was Samoan which gave Gavin and Paul their qualification.
Then there are twins.
In 2002 in an exhibition match in Bermuda, England-born Jane Mitchell played for the USA against twin sister Emma Mitchell who was playing for England.
Then there are the three Ma'afu brothers who each play for a different country.
Prop Salesi has played for Australia, Campese Ma'afu, named after the great Wallaby, for Fiji, youngest brother Apakuka for Tonga.
They are all born in Australia of a Fijian mother and a Tongan father. Salesi and Campese actually made their Test debuts scrumming against each other in 2010, Campese a loosehead, Salesi a tighthead.
They were cheek to cheek, as the Strausses will be in Dublin.
Oh and it's not quite the end of the Strausses, for Richardt's brother Andries is a Springbok, having played for the Springboks against the Barbarians in 2010.
By Paul Dobson