 Complete the following phrase:  In 1384 Archibald attacked and took Lochmaben Castle, the last English stronghold in south-west Scotland, and in 1388 he inherited the title of 3rd Earl of Douglas. He thus became the most powerful magnate in the country, controlling lands across southern Scotland and castles including Douglas Castle and Bothwell Castle in Lanarkshire. He funded a rebuilding of Sweetheart Abbey near Dumfries, and contracted marriages for his children with the offspring of King Robert III. Although he probably spent relatively little time at Threave, he died there in 1400, the first historical reference to the castle. He was succeeded by his son Archibald, who in 1390 had married Princess Margaret, daughter of Robert III. In 1424 he led a Scottish force to fight the English in France where he was killed at the 