Maria I of Portugal forced Portugal to cede Olivença and other border towns to Spain. (This cession is not recognized by the present Portuguese government, and the country officially considers those territories still to be Portuguese possessions.) On September 29, 1801 John VI signed the Treaty of Madrid (1801), ceding half of Guyana to France, which became French Guiana. The refusal of the Portuguese government to join the French-sponsored Continental Blockade against Britain culminated in the late 1807 Franco-Spanish invasion of Portugal led by General Junot. The ultimate Napoleonic plan for Portugal was to split it into three sections. The northern parts of Portugal,
Border Reivers were other factors which promoted a predatory mode of living in the Borders. A system of inheritance called gavelkind meant that estates, and particularly land, were divided equally between all sons on a man's death; although this was considered more fair than primogeniture, it also meant that many people owned insufficient land to survive. Also, much of the border region is mountainous or open moorland, unsuitable for arable farming but good for grazing. Livestock was easily rustled and driven back to raiders' territory by mounted reivers who knew the country well. The raiders also often removed easily portable household goods