William 'the Conqueror' died, in Normandy, on 9th September, 1087. His second surviving son, William 'Rufus', inherited the kingdom of England, whilst his estranged eldest son, Robert 'Curthose', had to be content with the duchy of Normandy. William Rufus brought, the recently released, Wulfnoth and Morcar to England with him:
"... but as soon as he arrived at Winchester, he put them into custody as before ..."
Geffrei Gaimar states that Morcar "died in his long imprisonment". There is no evidence to the contrary. William of Malmesbury says that Wulfnoth "grew old in confinement at Salisbury". Orderic Vitalis says that Wulfnoth died at Salisbury - noting that he "died honourably in the true faith".  Wulfnoth is the subject of an epigram, by Godfrey of Cambrai (prior of St.Swithin's, Winchester 1082-1107), which contains the lines:
Exile, prison, darkness, inclosure, chains
Receive the boy and forsake the old man.
Caught up in human bonds he bore them patiently,
Bound even more closely in service to God.
Wulfnoth was obviously well known at St.Swithin's, and he might well have become a monk. The positioning of his epigram in Godfrey's work suggests that Wulfnoth's death was c.1094.
In contrast, when Robert returned to Normandy, he supervised the release of:
"... Ulf, son of Harold, once king of the English, and Duncan, son of Malcolm, king of Scots, and honoured them with knighthood, and permitted them to depart."
Florence of Worcester
No more is heard of Ulf. Duncan was a son of Malcolm by his first wife, Ingibjorg.
The crown had barely settled on William's head (his coronation was on 26th September 1087) before he faced a rebellion by most of the Norman magnates of England. The plot, to replace William with Robert, was hatched in the spring of 1088, and its chief instigator was, William and Robert's uncle, Bishop Odo of Bayeux (who, since his release, had resumed his position as earl of Kent). In the event, William defeated the rebels, and Odo:
"... went over sea, and the bishop thus abandoned the dignity that he had in this land."
William determined to wrest Normandy from Robert, and, in February 1091, he crossed the Channel. However, the brothers came to terms - agreeing, amongst other things, that if one brother died without a legitimate son, the surviving brother would be his heir:
"In the midst of this treaty was Edgar the Ętheling deprived of the land that the earl [Robert] had before permitted him to keep in hand; and he went out of Normandy to the king [Malcolm III], his sister's husband, in Scotland, and to his sister [Margaret]. Whilst the King William was out of England ....
"In the month of May", says Florence of Worcester.
.... the King Malcolm of Scotland came hither into England, and overran a great deal of it, until the good men that governed this land sent an army against him and repulsed him. When the King William in Normandy heard this, then prepared he his departure, and came to England, and his brother, the Earl Robert, with him; and he at once ordered an army to be called out, both a naval-force and a land-force; but almost all the naval-force, ere it could come to Scotland, perished miserably, a few days before St.Michael's mass [29th September]....
Florence of Worcester adds that "many of his horsemen perished from cold and hunger."
.... And the king and his brother proceeded with the land-force; but when the King Malcolm heard that they were resolved to seek him with an army, he went with his force out of Scotland into Lothian in England, and there abode. When the King William came near with his army, then interceded between them Earl Robert, and Edgar the Ętheling, and so made the peace of the kings, that the King Malcolm came to our king, and did homage, promising all such obedience as he formerly paid to his father; and that he confirmed with an oath. And the King William promised him in land and in all things whatever he formerly had under his father....
Florence of Worcester is more specific: "... William should restore to Malcolm twelve townships which he had held under his father in England, and should pay him yearly the sum of twelve marks of gold."
.... In this settlement was also Edgar the Ętheling united with the king. And the kings then parted in great accord; yet that stood but a little while. And the Earl Robert tarried here full nigh until Christmas with the king, and during this time found but little of the truth of their agreement; and two days before that festival he took ship in the Isle of Wight, and went into Normandy, and Edgar the Ętheling with him."
'Anglo-Saxon Chronicle'
1093:
"... the king of Scotland sent and demanded the fulfilment of the treaty that was promised him. And the King William summoned him to Gloucester, and sent him hostages to Scotland, and Edgar the Ętheling afterwards; and the men returned, that brought him with great dignity to the king....
Florence of Worcester: "Malcolm, king of Scots, on the day of the feast of St.Bartholomew Apostle [24th August], met the king in the city of Gloucester ..."
.... But when he came to the king, he could not be considered worthy either of our king's speech, or of the conditions that were formerly promised him. For this reason therefore they parted with great dissatisfaction, and the King Malcolm returned to Scotland. And soon after he came home, he gathered his army, and came harrowing into England with more hostility than behoved him; and Robert [de Mowbray], the earl of Northumberland, surrounded him unawares with his men, and slew him."
'Anglo-Saxon Chronicle'
Malcolm, king of Scots, and his eldest son Edward, with many others ....
According to Geffrei Gaimar, there were "nearly three thousand men in number killed with Malcolm", and "many noble barons" were killed on both sides.
.... were slain in Northumbria on the feast of St.Brice [13th November] ..."
Florence of Worcester
"In his death the justice of an avenging God was plainly manifested; for this man perished in that province which he had often been wont to ravage ... he invaded Northumbria with as large an army as he could collect, intending to bring upon it utter desolation; but he was cut off near the river Alne ....
Geffrei Gaimar says the battle was at Alnwick.
.... with his eldest son Edward, whom he had appointed heir to the kingdom after him. His army either fell by the sword, or those who escaped the sword were carried away by the inundation of the rivers, which were then more than usually swollen by the winter rains. Two of the natives placed the body of the king on a cart, as none of his men were left to commit it to the ground, and buried it at Tynemouth."
William of Malmesbury writes: "For many years he [Malcolm] lay buried at Tynemouth: lately he was conveyed by Alexander [reigned 1107-24] his son to Dunfermline, in Scotland."  John of Fordun maintains that Malcolm's son, Edward, though mortally wounded at Alnwick, actually died "the third day after his father - at Edwardisle, in the forest of Jedwart [Jedwood]". John says that Edward was buried beside his father at Dunfermline. Matthew Paris (d.1259), however, notes that, in 1257: "... whilst the foundations of some buildings were being laid at Tynemouth, a priory of St.Albans, the bones of Malcolm, king of Scots, and his son Edward, were found."  Further, Matthew claims that, when the Scots had "arrogantly demanded" that they be given Malcolm's body, the Tynemouth authorities palmed them off with "the body of a man of low birth", called Sethtune: "and so the arrogance of the Scots was deceived".
"When she heard of their death, Margaret, queen of Scots, was so heavily affected with sorrow, that she suddenly fell into a serious sickness. Without delay, she summoned the priests, entered the church, and having confessed her sins to them, caused herself to be anointed with oil and strengthened with the heavenly viaticum, beseeching God with the most earnest and heartfelt prayers, that He would not suffer her to live longer in this world of trouble. Nor was it very long before her prayers were heard; for in three days after the death of the king, she was released from the bonds of the flesh, and passed (as we believe) to the joys of eternal salvation. While she lived, she was a faithful labourer in deeds of piety, justice, peace, and charity; she was frequent in prayer; she kept her body in subjection by vigils and fastings; she endowed churches and monasteries, loved and honoured the servants and handmaidens of God, broke bread to the hungry, clothed the naked, gave lodging, clothing and food to the strangers who came to her, and loved God with all her soul."
Florence of Worcester
Margaret was buried at Dunfermline. In 1249 she was canonised, and, on 19th June 1250, her remains were moved to "a shrine of deal, set with gold and precious stones" (John of Fordun).
"And the Scots then chose Dufenal [Donald] to king, Malcolm's brother, and drove out all the English that formerly were with the King Malcolm. When Duncan, King Malcolm's son, heard all that had thus taken place (he was then in the King William's court, because his father had given him as a hostage to our king's father, and so he lived here afterwards), he came to the king, and did such fealty as the king required at his hands; and so with his permission went to Scotland, with all the support that he could get of English and French, and deprived his kinsman Dufenal of the kingdom, and was received as king. But some of the Scots afterwards gathered, and slew full nigh all his men; and he himself with a few made his escape. Afterwards they were reconciled, on the condition that he never again brought into the land English or French."
Anglo-Saxon Chronicle
1094:
"... the Scots ensnared their king, Duncan, and slew him; and afterwards, the second time, took his paternal uncle Dufenal to king, through whose instruction and advice he [Duncan] was betrayed to death."
'Anglo-Saxon Chronicle'
Meanwhile, Robert's patience with his brother had run out, and he demanded that William stick to the bargain they had earlier made. In 1094 ("about mid-Lent" says the 'Chronicle'), William travelled to Normandy, but he and Robert could not come to an agreement, and hostilities broke out. Apparently prompted by a Welsh rebellion, William returned to England on 29th December. In the spring of 1095, William's younger brother, Henry, travelled to Normandy, in William's stead, to carry on the fight against their brother Robert. In 1096, Robert pawned Normandy to William in order to finance his participation in the First Crusade.
Florence of Worcester: "And William crossed the sea in the month of September, made peace with his brother, lent him six thousand six hundred and sixty-six pounds, and received Normandy as security."  Bishop Odo also set out for the Holy Land, but died en route, at Palermo, early in 1097.
1097:
"... soon after Michaelmas [29th September] went Edgar the Ętheling with an army through the king's assistance into Scotland, and with hard fighting won that land, and drove out the King Dufenal; and his kinsman Edgar, who was son of King Malcolm and of Margaret the queen, he there appointed king in fealty to the King William; and afterwards again returned to England."
Anglo-Saxon Chronicle
Subsequently, Edgar the Ętheling joined the Crusade.
1100:
"... on the morning after Lammas day [i.e. on 2nd August] was the King William shot in hunting, by an arrow from one of his own men, and afterwards brought to Winchester, and buried in the cathedral... On the Thursday he was slain; and in the morning afterwards buried; and after he was buried, the statesmen that were then nigh at hand, chose his brother Henry to king."
'Anglo-Saxon Chronicle'
Henry was crowned, at Westminster, on 5th August.
"During the harvest of this same year also came the Earl Robert home into Normandy ... from Jerusalem. And as soon as the Earl Robert came into Normandy, he was joyfully received by all his people; except those of the castles that were garrisoned with the King Henry's men. Against them he had many contests and struggles."
Anglo-Saxon Chronicle
On 11th November, Henry married Matilda (also known as Maud and, her original name, Edith) - daughter of Malcolm and Margaret. As the 'Chronicle' points out, she was "the relative of King Edward, and of the right royal race of England"  She was, of course, Edgar the Ętheling's niece.
Henry did not enjoy universal support, however, and, in 1101, Robert was encouraged to mount an invasion of England. On 20th July he landed at Portsmouth, and Henry marched to meet him. Battle was averted when "the wiser men of both sides" (Florence of Worcester) brokered a peace between the brothers. "After Michaelmas" ('Anglo-Saxon Chronicle') Robert returned to Normandy. In 1104, Henry and Robert were, once more, at odds, and, in the spring of 1105, Henry:
"... went over sea into Normandy against his brother Earl Robert. And whilst he remained there he won of his brother Caen and Bayeux; and almost all the castles and the chief men in that land were subdued. And afterwards by harvest he returned hither again ..."
Anglo-Saxon Chronicle
1106:
"... before Lent was the king at Northampton; and the Earl Robert his brother came thither from Normandy to him; and because the king would not give him back that which he had taken from him in Normandy, they parted in hostility; and the earl soon went over sea back again... before August, went the king over sea into Normandy ..."
Anglo-Saxon Chronicle
The final showdown between Henry and Robert was the battle of Tinchebray, which was fought on 28th September, and in which Henry was victorious:
"There was the earl of Normandy taken ... and afterwards sent to England, and put into custody... Edgar the Ętheling, who a little before had gone over from the king to the earl, was also there taken, whom the king afterwards let go unpunished. Then went the king over all that was in Normandy, and settled it according to his will and discretion."
'Anglo-Saxon Chronicle'
Edgar the Ętheling took no further active part in the making of British history. In the 'Gesta Regum Anglorum', William of Malmesbury writes that Edgar "now grows old in the country in privacy and quiet" (perhaps in Hertfordshire, where 'Domesday Book' lists him as a landholder).
Robert remained a prisoner for the rest of his life. 1134:
"Robert, brother of king Henry, formerly earl of Normandy ... died at Cardiff, was carried to Gloucester, and buried in the pavement of the church, before the altar, with great honour."
Florence of Worcester
King Henry died in 1135.
Translations:
Symeon of Durham 'Historia Regum' by J. Stevenson
Orderic Vitalis 'Historia Ecclesiastica' by Marjorie Chibnall
Geffrei Gaimar 'L'Estoire des Engleis' by Rev. Joseph Stevenson
Matthew Paris 'Chronica Majora' and 'Additamenta' by Rev. J.A. Giles
'Anglo-Saxon Chronicle' based on that by Rev. James Ingram/Dr. J.A. Giles
John of Fordun 'Chronica Gentis Scotorum' by Felix J.H. Skene, edited by W.F. Skene
William of Malmesbury 'Gesta Regum Anglorum' by Rev. J. Sharpe, revised by Rev. J. Stevenson
Florence of Worcester 'Chronicon ex Chronicis' edited and in part translated by Joseph Stevenson