From The Normans in Europe:
On the accession of young Richard he was surrounded by great dangers. The old Northern non-observance of religious marriage rites between his parents laid him open to the imputation of bastardy. The ambiguous position was undoubtedly an element of difficulty. There were enemies enough who gladly seized the opportunity of disputing Richard's inheritance, and Leutgarda, who had married Theobald of Blois, pursued her stepson all her life with the hostility traditional of a stepmother.
Fortunately for Richard, he was amongst the faithful friends of his father, Bernard the Dane, Ivo de Bellesme, and Osmund de Centville. Louis of France and Hugh of Paris united to reduce Normandy. Accordingly, the duchy was invaded, the Danish party overthrown, Rouen seized, and Louis gained possession of young Richard, while Hugh secured Evreux. Richard was sent prisoner to Laon, from which, aided by his trusty companion, Osmund, he escaped hidden in a truss of hay, and the standard of revolt was raised - 945.
Fortunately for Richard, in his hour of peril, Harald Bluetooth, King of Denmark, grandfather of Knut the Great, appeared on the coast, rallied the Normans round his standard (945), and meeting Louis on the Dive, utterly routed his forces. Louis, made prisoner in personal combat with Harald, succeeded in escaping, only to fall in the hands of other enemies. Harald, after passing through the land confirming the authority of the young Duke, returned to his northern home.
The next year (946) Hugh of Paris, anxious to secure the alliance of Richard, betrothed to him his young daughter Emma, and Richard thereon commended himself to Hugh, whose influence in France now became supreme. In 956 Hugh died, leaving by will, his son Hugh Capet, a boy of 13, hereafter King of France, under the guardianship of Richard, and the alliance was cemented in 960 by the consumation of the marriage between Emma and Richard.
The rest of Richard's reign was comparatively quiet, if we except a short war with England in 991. This is said to have been caused by the shelter offered by Richard to the Danes who, under Sweyn of Denmark, son of Harald Bluetooth, were again beginning to trouble England, and entering on that political conquest which culminated in the establishment of Knut upon the English throne. The war was soon put an end to by the mediation of the Pope, and is important only as forming the first instance in which the Norman dukes were brought into direct connection with the English kings.
Richard had no children by Emma, but by Guenora, to whom he had been united in the Northern way, he had a numerous progeny. He eventually married her according to Christian rites, and by the doctrine of the Church, his children became legitimatised. Of these,
NOTE - Palgrave in enumerating the descendants of Richard I of Normandy, Sans Peur, states, "Mauger who acquired much importance in French affairs was assuredly legitimate" and again, "Mauger, much distinguished by his policy and valour, was invested with the extensive County of Mortaigne as an inheritance, while through marriage he acquired Corbeil". [from The Sinclairs of England]