Reginald I of Guelders. was Count of Guelders from January 10 1271 until his death.

He was the son of Otto II, Count of Guelders

Otto II, Count of Guelders

Otto II, Count of Guelders was a nobleman from the 13th century. He was the son of Gerard III, Count of Guelders and Margaretha of Brabant.-Life:...

 and Philippe of Dammartin

Philippe of Dammartin

Philippe of Dammartin was a 13th century noble woman. Philippe was the daughter of Simon of Dammartin, Count of Aumâle, Count of Ponthieu and of Montreuil and his wife Marie of Ponthieu...

.

In 1276 he married Irmgard of Limburg, only daughter and heiress of Waleran IV, Duke of Limburg.
In 1279 he became Duke-consort of Limburg and when Irmgard died childless in 1283, he became the only ruler of the Duchy of Limburg

Duchy of Limburg

The Duchy of Limburg, situated in the Low Countries between the river Meuse and the city of Aachen, was a state of the Holy Roman Empire. Its territory is now divided between the Belgian provinces of Liège and Limburg , the Dutch province of Limburg , and a small part of North Rhine-Westphalia in...

. He lost this title after losing the Battle of Woeringen in 1288.

In 1286 he remarried Margaret of Flanders (1272-1331), daughter of Guy, Count of Flanders and widow of Alexander, Prince of Scotland. they had 5 children:

• Reginald II (1295-1343)
• Margaret, married Dietrich VIII, Count of Cleves
  Dietrich VIII, Count of Cleves
  Dietrich VIII was Count of Cleves from 1310 through 1347.The County of Cleves was a comital polity of the Holy Roman Empire in present Germany and the Netherlands . Its rulers, called counts, had a special and privileged standing in the Empire...
  
  
• Guy
• Elisabeth (died 1354), abbess at Cologne
• Philippa, nun at Cologne.

Financially ruined after the Battle of Woeringen, Guelders came under the influence of his father-in-law, the Count of Flanders.
From 1318, he was replaced by his son, who imprisoned his father in 1320 in the Montfort Castle.
Reginald I died here 6 years later.