Kedah (kəˈdɑh), also known by its honorific Darul Aman and historically as Queda, is a state of Malaysia, located in the northwestern part of Peninsular Malaysia. The state covers a total area of over 9,000 km2, and it consists of the mainland and the Langkawi islands. The mainland has a relatively flat terrain, which is used to grow rice, while Langkawi is an archipelago, most of which are uninhabited islands.
Kedah was previously known as Kadaram (கடாரம்; ISO) by the ancient and medieval Tamils, Kataha or Kalahbar (قتح; ISO or قلحبر; ISO) by the Arabs, and Syburi (ไทรบุรี; ) by the Siamese when it was under their influence.
To the north, Kedah borders the state of Perlis and shares an international boundary with the Songkhla and Yala provinces of Thailand. It borders the states of Perak to the south and Penang to the southwest.
The state's capital is Alor Setar and the royal seat is in Anak Bukit. Other major towns include Sungai Petani (its largest urban area by population), and Kulim on the mainland, and Kuah on Langkawi.
Around 788 BCE, a systematic government of a large settlement had already established around the northern bank of Merbok River. The state consisted a large area of Bujang Valley, covering Merbok and Muda River branches about 1000 square miles area. The capital of the settlement was built at the estuary of a branch of Merbok River, now known as Sungai Batu. Archaeological evidence found in Bujang Valley (Malay: Lembah Bujang) reveals that an animist kingdom ruled ancient Kedah possibly as early as 110 A.D. The discovery of temples, jetty remains, iron smelting sites, and clay brick monuments dating back to 110 A.D shows that a maritime trading route with south Indian Tamil kingdoms was already established since that time. The discoveries in Bujang Valley also made the ancient Kedah as the oldest civilisation of Southeast Asia.
Ancient Kedah was first mentioned in the Tamil poem Paṭṭiṉappālai written at the end of the second century A.D. It described goods from Kadaram "heaped together in the broad streets" of the Chola capital.