 
 <prompt> "Where dem see treasures? Based on di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context:" <response>: E fit be say di most popular raid by Oeselian pirates happun for 1187, wit di attack on di Swedish town of Sigtuna by Finnic raiders from Couronia and Oesel. Among di people wey die for dis raid na di Swedish archbishop Johannes. Di city dey occupied for some time, wey lead to e decline as a center of commerce for di 13th century and di rise of Uppsala, Visby, Kalmar and Stockholm. Di Livonian Chronicle describe di Oeselians as people wey dey use two kinds of ships, di piratica and di liburna. Di piratica na warship, while di liburna na mainly merchant ship. A piratica fit carry like 30 men and get high prow wey be like dragon or snakehead and rectangular sail. Viking-age treasures from Estonia mostly dey contain silver coins and bars. Saaremaa get di richest finds of Viking treasures afta Gotland for Sweden. Dis one strongly suggest say Estonia na important transit country during di Viking era. 