Zuiderzee came in the Burgundian period to rank among the busiest towns of Holland-Hoorn as the chief market in the Netherlands for dairy produce and cattle, Enkhuizen as a centre of the herring-fishery. Friesland proper, on the north-eastern shore, over which Philip asserted his claims as Count of Holland and Zeeland, was not actually absorbed by him. Here the party-name of the Schieringers mainly applied to the lower population settled round the waters of the ancient Westergao, and that of the Veikoopers to the men of substance in and around Groningen, which town held a position so distinctive that it afterwards became eponymous of a whole province (officially called stadt en landen). Philip the Good might possibly have been acknowledged as Lord of Friesland, like John of Bavaria before him, had he been prepared to bind himself to respect the liberties of the population. But this he consistently refused, and the remote region was once more left to itself. Even the subsequent recognition by Groningen of the overlordship of the Bishop of Utrecht was purely nominal; as was the episcopal protection claimed by her against the attempt of Charles the Bold to assert the ducal authority over all West-Friesland (1469.) From the renewed internal party-conflicts in Friesland Groningen discreetly held aloof, intent upon the advancement of her commercial prosperity, by whose side that of ancient "golden" Stavoren was passing away, while that of Leeuwarden had hardly yet begun.
Philip's last important territorial acquisition was that of the duchy of Luxemburg, a sparsely peopled land of mountains and forests whose capital derived importance from the incomparable natural strength of its position. It had been twice temporarily united with Brabant-first under Wenceslas, upon whom it had been bestowed by his brother, the great Emperor Charles IV, and who was married to the heiress Joan; and then under Elizabeth, niece of the second Wenceslas, King of the Romans, who had left it very much to itself and the protection of its natural outworks, the wild Ardennes. To her (commonly called Elizabeth of Gorlitz) he had, after her marriage to Duke Anthony of Brabant, Philip's younger brother, made over his rights in Luxemburg; and since both Anthony and her second husband, John of Bavaria, formerly Bishop-elect of Liege, left her a childless widow, her duchy was plainly marked out for incorporation in the Burgundian dominions. In 1445 Philip purchased it from Elizabeth, who, after he had averted an extraneous attack and established his authority in every part of the duchy, made a formal donation to him of the whole.
Of the four great dioceses into which the Netherlands were up to the time of Charles V divided, Liege and Utrecht retained the character of self-governed ecclesiastical principalities beyond the duration of Philip's reign. Liege (Luik) was one of the most important sees in the Empire, and the spiritual authority of its Bishop extended