Robert IV of Dreux Count of Dreux, Braine and Montfort-l'Amaury, was the son of John I of Dreux

John I of Dreux

John I of Dreux , Count of Dreux and Braine, was the son of Robert III of Dreux and Annora of Saint-Valéry.Knighted by King Louis IX of France, he accompanied the king on several campaigns, firstly in Poitou in 1242, where he fought at the Battle of Taillebourg...

 and Marie of Bourbon.

Robert fought with Philip III of France

Philip III of France

Philip III , called the Bold , was the King of France, succeeding his father, Louis IX, and reigning from 1270 to 1285. He was a member of the House of Capet.-Biography:...

 in 1272 in his expedition to the Languedoc

Languedoc

Languedoc is a former province of France, now continued in the modern-day régions of Languedoc-Roussillon and Midi-Pyrénées in the south of France, and whose capital city was Toulouse, now in Midi-Pyrénées. It had an area of approximately 42,700 km² .-Geographical Extent:The traditional...

 and was present at the capture of Foix

Foix

Foix is a commune, the capital of the Ariège department in southwestern France. It is the least populous administrative centre of a department in all of France, although it is only very slightly smaller than Privas...

.

In 1260 he married Beatrice de Montfort, Countess of Montfort-l'Amaury

Beatrice de Montfort, Countess of Montfort-l'Amaury

Beatrice de Montfort, Countess of Montfort-l'Amaury was the wife of Robert IV of Dreux, Count of Dreux , and the ancestress of the Dukes of Brittany from the House of Montfort-Dreux which derived its name from her title.- Family :Beatrice was born sometime between December 1248 and 1249, the only...

 daughter of Jean I de Montfort

Jean I de Montfort

Jean I de Montfort , Comte de Montfort from 1241 to 1249, son of Amaury VI, comte de Montfort, and of Béatrice de Bourgogne.In March 1248 he married Jeanne de Châteaudun, dame de Château-du-Loir, daughter of Geoffroy VI, vicomte de Châteaudun, and of Clémence des Roches...

 and Jeanne, Dame de Chateaudun

Jeanne, Dame de Chateaudun

Jeanne, Dame de Chateaudun was a French heiress and the wife of two French noblemen Jean I de Montfort, and Jean de Brienne, Grand Butler of France.- Family :...

, and granddaughter of Amaury de Montfort

Amaury de Montfort

Amaury VI de Montfort was the son of the elder Simon de Montfort and Alice of Montmorency, and the brother of the younger Simon de Montfort.He participated in the Albigensian Crusade under his father's command...

. Their son John

John II of Dreux

John II of Dreux, called John the Good, , Count of Dreux and Braine was the son of Robert IV of Dreux and Beatrice, Countess of Montfort....

 succeeded his father while their eldest daughter Yolande (1263–1322) married Alexander III

Alexander III of Scotland

Alexander III was King of Scots from 1249 to his death.-Life:...

, King of Scots, and later Arthur II

Arthur II, Duke of Brittany

Arthur II , of the House of Dreux, was Duke of Brittany from 1305 to his death. He was the first son of John II and Beatrice, daughter of Henry III of England and Eleanor of Provence....

, Duke of Brittany

Duke of Brittany

The Duchy of Brittany was a medieval tribal and feudal state covering the northwestern peninsula of Europe,bordered by the Alantic Ocean on the west and the English Channel to the north with less definitive borders of the Loire River to the south and Normandy to the east...

.

List of children

1. Marie de Dreux (1261–1276), married in 1275 Mathieu IV de Montmorency
2. Yolande of Dreux, Countess de Montfort (1263–1323), married firstly on 15 October 1285 King Alexander III of Scotland
   Alexander III of Scotland
   Alexander III was King of Scots from 1249 to his death.-Life:...
   
   , and secondly in 1292 Arthur II, Duke of Brittany
   Arthur II, Duke of Brittany
   Arthur II , of the House of Dreux, was Duke of Brittany from 1305 to his death. He was the first son of John II and Beatrice, daughter of Henry III of England and Eleanor of Provence....
   
   . Had seven children by her second husband
3. John II of Dreux
   John II of Dreux
   John II of Dreux, called John the Good, , Count of Dreux and Braine was the son of Robert IV of Dreux and Beatrice, Countess of Montfort....
   
    (1265–1309), married firstly Jeanne de Beaujeu, Dame de Montpensier (died 1308), by whom he had four sons and one daughter, in 1308 he married secondly Perrenelle de Sully, by whom he had one daughter Jeanne II, Countess of Dreux (1309 – c. 1355)
4. Jeanne, Countess de Braine, married firstly Count Jean IV de Roucy, and secondly John of Bar
5. Beatrice de Dreux (1270–1328), Abbess of Pont-Royal
6. Robert de Dreux, seigneur de Cateau-du-Loire