Wareru
ဝါရေဝ်ရောဝ်
ဝါရီရူး
King of Martaban
Reign30 January 1287 – c. 14 January 1307
Coronation5 April 1287
Predecessornew office
SuccessorHkun Law
Chief MinisterLaik-Gi (1287–c. 1296)
Ruler of Martaban
Reignc. 11 January 1285 – 30 January 1287
PredecessorAleimma (as governor)
Successordisestablished
Born20 March 1253
Thursday, 4th waning of Late Tagu 614 ME
Tagaw Wun
Pagan Empire
Diedc. 14 January 1307 (aged 53)
c. Saturday, 11th waxing of Tabodwe 668 ME
Martaban (Mottama)
Martaban Kingdom
ConsortMay Hnin Thwe-Da
Shin Saw Hla
IssueMay Hnin Theindya
HouseWareru
ReligionTheravada Buddhism

Wareru (Mon: ဝါရေဝ်ရောဝ်, Burmese: ဝါရီရူး, Burmese pronunciation: [wàɹíjú]; also known as Wagaru; 20 March 1253 – c. 14 January 1307) was the founder of the Martaban Kingdom, located in present-day Myanmar (Burma). By using both diplomatic and military skills, he successfully carved out a Mon-speaking polity in Lower Burma, during the collapse of the Pagan Empire (Bagan Empire) in the 1280s. The king was assassinated in 1307 but his line ruled the kingdom until its fall in the mid-16th century.

Wareru, a commoner, seized the governorship of Martaban (Mottama) in 1285, and after receiving the backing of Sukhothai, he went on to declare independence from Pagan in 1287. In 1295–1296, he and his ally Tarabya, the self-proclaimed king of Pegu (Bago), decisively defeated a major invasion by Pagan. Wareru eliminated Tarabya soon after, and emerged as the sole ruler of three Mon-speaking provinces of Bassein, Pegu and Martaban c. 1296. With his domain now much enlarged, Wareru sought and received recognition by the Mongols (Yuan China) in 1298.

Although he may have been of ethnic Mon or Shan background, Wareru's greatest legacy was the establishment of the only Mon-speaking polity left standing after the 1290s. The success of the kingdom helped foster the emergence of the Mon people as a coherent ethnicity in the 14th and 15th centuries. Furthermore, the legal code he commissioned—the Wareru Dhammathat—is one of the oldest extant dhammathats (legal treatises) of Myanmar, and greatly influenced the legal codes of Burma and Siam down to the 19th century.