Richard was born on 2 October 1452 at Fotheringhay Castle, the twelfth of thirteen children of Richard Plantagenet, 3rd Duke of York and Cecily Neville at the beginning of what has traditionally been labelled the "Wars of the Roses", a period of "three or four decades of political instability and periodic open civil war in the second half of the fifteenth century", between supporters of Richard's father (a potential claimant to the throne of King Henry VI from birth)--"Yorkists"--in opposition to the regime of Henry VI and his wife, Margaret of Anjou, and those loyal to the crown ("Lancastrians"). When his father and the Nevilles were forced to flee to Ludlow in 1459, Richard and his older brother, George (later Duke of Clarence), were placed in the custody of the Duchess of Buckingham, and the Archbishop of Canterbury. When his father and elder brother Edmund, Earl of Rutland, were killed at the Battle of Wakefield on 30 December 1460, Richard, who was eight years old, and George were sent by his mother, the Duchess of York, to the Low Countries. They returned to England following the defeat of the Lancastrians at the Battle of Towton and participated in the coronation of Richard's eldest brother as King Edward IV in June 1461.
Reburial and tomb
In 1485, following his death in battle against Henry Tudor at Bosworth Field, Richard III's body was buried in Greyfriars Church in Leicester.  Following the discoveries of Richard's remains in 2012, it was decided that they should be reburied at Leicester Cathedral, despite feelings in some quarters that he should have been reburied in York Minster. His remains were carried in procession to the cathedral on 22 March 2015, and reburied on 26 March 2015 at a religious re-burial service at which both the Right Reverend Tim Stevens, the Bishop of Leicester, and the Most Reverend Justin Welby, the Archbishop of Canterbury, officiated. The British Royal Family was represented by the Duke and Duchess of Gloucester and the Countess of Wessex. The actor Benedict Cumberbatch, who is a distant relation of the king and later portrayed him in The Hollow Crown television series, read a poem by Poet Laureate Carol Ann Duffy.  His cathedral tomb was designed by the architects van Heyningen and Haward. The tombstone is deeply incised with a cross, and consists of a rectangular block of white Swaledale fossil stone, quarried in North Yorkshire. It sits on a low plinth made of dark Kilkenny marble, incised with Richard's name, dates and motto (Loyaulte me lie - loyalty binds me). The plinth also carries his coat of arms in pietra dura. The remains of Richard III are in a lead-lined coffin, inside an outer English oak coffin crafted by Michael Ibsen, a direct descendant of Richard's sister Anne of York, and laid in a brick-lined vault below the floor, and below the plinth and tombstone. The original 2010 raised tomb design had been proposed by Langley`s "Looking For Richard Project" and fully funded by members of the Richard III Society. The proposal was publicly launched by the Society on 13 February 2013 but rejected by Leicester Cathedral in favour of a memorial slab. However, following a public outcry, the Cathedral changed its position and on 18 July 2013 announced its agreement to give King Richard III a raised tomb monument.

Q: Why was reburial necessary?
A: it was decided that they should be reburied at Leicester Cathedral,

Q: Where were they buried before?
A: Greyfriars Church in Leicester.
Does they mean the remains of Richard III?
Richard III's body was buried in Greyfriars Church in Leicester.
Richard III's body was buried in Greyfriars Church in Leicester.