What is "brokmerland"

The Brokmerland is a landscape and an historic territory, located in western East Frisia, which covers the area in and around the present-day communities of Brookmerland and Südbrookmerland. The Brokmerland borders in the east on the Harlingerland and in the north on the Norderland. The historic Brokmerland is usually written with only one "o". Occasionally one also finds the spelling "Broekmerland" ("oe" pronounced as a long "o"), while today's communities have chosen to spell the name with a double "o".