Donnchadh of Lennox was the Mormaer of Lennox, 1385–1425. He was a son of Baltar mac Amlaimh and Margaret, daughter of Domhnall, Earl of Lennox. When Domhnall of Lennox died in 1365, Donnchadh's mother Margaret became ruler of Lennox. It had been Domhnall's intention that the marriage would eventually allow the succession of a son, i.e. Donnchadh, but it is probable that Baltar intended to rule in his turn. It is not known how relations deteriorated, but it seems that Donnchadh got impatient. In the summer of 1384, King Robert II issued two charters formally conferring the Mormaerdom on Baltar. However, a year later he and his wife Margaret resigned the Mormaerdom over to their eldest son Donnchadh, and hence Donnchadh became ruler. However, in 1388, Baltar and Margaret were handed custody