In Indonesia, Srivijaya from the 7th through 14th century was a Thalassocracy that focused on maritime city states and trade. Controlling the vital choke points of the Sunda and Malacca straits it became rich from trade ranging from Japan through Arabia. Gold, Ivory and Ceramics were all major commodities traveling through port cities. The Empire was also responsible for the construction of wonders such as Borobudur. During this time Indonesian sailors crossed the Indian Ocean; evidence suggests that they may have colonized Madagascar. Indian culture spread to the Philippines, likely through Indonesian trade resulting in the first documented use of writing in the archipelago and Indianized kingdoms.