The Maasgau, Masao, or Maasland, was an early medieval region or pagus, on both sides of the Meuse (Dutch: Maas), stretching north of the city of Maastricht.
According to Nonn's collection of attestations: As pointed out by Verhelst, the term Masalant (Maasland) is used mainly when referring to Maastricht, and according to him it is only used by mistake in the 950 case above.
In 889, 898 and 919, Maastricht is specifically described as being in the comitatus (county) of Maselant.
In the 898 record it is also added that it is in the Pagus of Hasbania.
In contrast, in another 919 record it is described as being in the comitatus of Hasbania.