Robert was the eldest son of William the Conqueror, the first Norman king of England, and Matilda of Flanders.

Estimates of Robert's birth-date range between 1051 and 1053.
As a child he was betrothed to Margaret, the heiress of Maine, but she died before they could be wed, and Robert did not marry until his late forties.
In his youth he was reported to be courageous and skilful in military exercises.
He was, however, also prone to laziness and weakness of character that discontented nobles and the King of France exploited to stir discord with his father William.
He was unsatisfied with the share of power allotted to him and quarrelled with his father and brothers fiercely.
In 1063, his father made him the Count of Maine in view of his engagement to Margaret, and Robert may have had independent rule in Maine.
The county remained under Norman control until 1069 when the county revolted and reverted to Hugh V of Maine.

In 1077, Robert instigated his first insurrection against his father as the result of a prank played by his younger brothers William Rufus and Henry, who had dumped a full chamber-pot over his head.
Robert was enraged and, urged on by his companions, started a brawl with his brothers that was only interrupted by the intercession of their father.
Feeling that his dignity was wounded, Robert was further angered when King William failed to punish his brothers.
The next day Robert and his followers attempted to seize the castle of Rouen.
The siege failed, but, when King William ordered their arrest, Robert and his companions took refuge with Hugh of Chateauneuf-en-Thymerais.
They were forced to flee again when King William attacked their base at Rémalard.
Robert was the eldest son of William the Conqueror, the first Norman king of England, and Matilda of Flanders.
Estimates of Robert's birth-date range between 1051 and 1053. As a child he was betrothed to Margaret, the heiress of Maine, but she died before they could be wed, and Robert did not marry until his late forties. In his youth he was reported to be courageous and skilful in military exercises. He was, however, also prone to laziness and weakness of character that discontented nobles and the King of France exploited to stir discord with his father William. He was unsatisfied with the share of power allotted to him and quarrelled with his father and brothers fiercely. In 1063, his father made him the Count of Maine in view of his engagement to Margaret, and Robert may have had independent rule in Maine. The county remained under Norman control until 1069 when the county revolted and reverted to Hugh V of Maine.
In 1077, Robert instigated his first insurrection against his father as the result of a prank played by his younger brothers William Rufus and Henry, who had dumped a full chamber-pot over his head. Robert was enraged and, urged on by his companions, started a brawl with his brothers that was only interrupted by the intercession of their father. Feeling that his dignity was wounded, Robert was further angered when King William failed to punish his brothers. The next day Robert and his followers attempted to seize the castle of Rouen. The siege failed, but, when King William ordered their arrest, Robert and his companions took refuge with Hugh of Chateauneuf-en-Thymerais. They were forced to flee again when King William attacked their base at Rémalard.
Robert Curthose