Flanders
Flanders shares its borders with Wallonia in the south, Brussels being an enclave within the Flemish Region. The rest of the border is shared with the Netherlands (Zeelandic Flanders in Zeeland, North Brabant and Limburg) in the north and east, and with France (French Flanders in Hauts-de-France) and the North Sea in the west. Voeren is an exclave of Flanders between Wallonia and the Netherlands, while Baarle-Hertog in Flanders forms a complicated series of enclaves and exclaves with Baarle-Nassau in the Netherlands. Germany, although bordering Wallonia and close to Voeren in Limburg, does not share a border with Flanders. The German-speaking Community of Belgium, also close to Voeren, does not border Flanders either. (The commune of Plombières, majority French speaking, lies between them.)
County of Flanders
Initially the French kings meant to secure the safety of the northern French border from Viking invasions with this act. The counts, however, made good use of the crisis situation by incorporating the surrounding plundered territories into the county. The counts expanded the influence of the original Flemish "pagus" over the years over all territories south and west of the Scheldt river, including presentday the lordship of the Four Amts, Zeelandic Flanders, the burgraviate of Aalst to the east and the County of Artois to the south, which remained part of Flanders until it became a separate county in 1237. After that date, the county of Artois at various times still came under the dominion of the count of Flanders as a separate title, until it was absorbed by the French crown.