He was also an older brother of Maria of Brabant, Queen consort of Philip III of France.

In 1267 his older brother Henry IV, Duke of Brabant, being mentally deficient, was deposed in his favour.

[2] John I was said to be a model of feudal prince: brave, adventurous; excelling in every form of active exercise, fond of display, and generous in temper.

On 3 May 1294 at some marriage festivities at Bar-le-Duc, John I was mortally wounded in the arm in an encounter by Pierre de Bausner.

[2] He was buried in the church of the Order of Friars Minor (Minderbroederskerk) in Brussels, but since the Protestant iconoclasm (Beeldenstorm) in 1566, nothing remains of his tomb.