The English verb rob, meaning to steal (something) from (someone), is attested in the early 13th century.
It is from Anglo-Norman and Old-French forms such as robier, robber and rober, meaning to plunder (a town, village, etc.), to steal (something) from (someone).
Those Anglo-Norman and Old-French forms are from the Germanic base of the archaic English verb reave, meaning to plunder, to despoil, to rob [see footnote].
The English noun robe, denoting a long loose outer garment, is also attested in the early 13th century.
Curiously, robe is also from the Germanic base of reave, via Anglo-Norman and Old-French forms such as roube, robbe and robe (contemporary French robe), which originally meant booty, spoils.
The explanation is that, because clothing was an important component of booty, the French noun came to denote looted clothing, clothes taken from an enemy, hence, generically, clothing, clothes.
THE FRENCH VERBS DÉROBER AND VOLER (TO STEAL FROM)
The French verb rober, now obsolete, has been replaced by dérober, in which the prefix dé- is intensive.
(Likewise, the French verb démanger, meaning to itch, is a compound of the intensive prefix dé- and of the verb manger, meaning to eat: the literal sense of démanger is to eat up.)
But the more usual French verb used in the sense of to steal (something) from (someone) is voler (quelque chose) à (quelqu’un), attested in this sense in the early 16th century.
The sense development of voler is curious too, because, since the late 9th century, its primary meaning has been to fly—it is from the Latin verb vŏlāre, of same signification.
This French verb has come to also mean to steal from through falconry, in which voler has been used since the 14th century of a bird of prey that chases and seizes another bird.
Note: Based on reave, the verb bereave is currently used in the restricted sense to leave deprived of a close relation or friend through death.
It was originally used in the generic sense to deprive of, the prefix be- giving a privative force to the verb reave.
Likewise, the verb benumb, meaning to deprive of physical or emotional feeling, is from the past participle of the obsolete verb benim, meaning to take away, composed of the privative prefix be- and of the Old-English verb nim, meaning to take.