There is no such river as the Murray Darling River. The two rivers are quite separate and distinct, with the Darling a tributary of the Murray. The Darling River was named b
…y Charles Sturt early in 1829. During an expedition in which he traced the Macquarie River, Sturt arrived suddenly at what he described as "a noble river". This was the Darling, which he named after Governor Darling. The Murray River was originally called the Hume when it was discovered by Hume and Hovell in 1824. (Whether it was named by Hovell for his partner Hume, or by Hume for his father, remained a point of contention between the two for some time.) It became the Murray late in 1829 when Sturt discovered that the Murrumbidgee flowed into it, and charted the river. Sturt named it the Murray after Sir George Murray, Secretary of State for the Colonies at that time. (MORE) 
