Tykocin Castle The Tykocin Royal Castle is a 15th - century castle located on the right bank of the river Narew in Tykocin , Poland . It fell into ruin in the 18th century and its reconstruction began in 2002 . History . The castle was built in 1433 for the Lithuanian noble Jonas Goštautas , voivode of Trakai and Vilnius , replacing the original wooden fortress . In the 1560s , upon the death of the last member of the Goštautas family the castle became the property of king Sigismund II Augustus , who expanded it . The construction was supervised by Hiob Bretfus , military engineer and royal architect . During the reign of Sigismund Augustus the structure served as a royal residence with an impressive treasury and library as well as the main arsenal of the crown . In 1611 - 1632 the castle was rebuilt again and surrounded with bastion fortifications by Krzysztof Wiesiołowski , starosta of Tykocin . During the Deluge in 1655 the Radziwiłł army occupied the castle . On December 31 , 1655 , when the castle was besieged by troops of the Tyszowce Confederation , Janusz Radziwiłł , one of the most powerful people in the Polish – Lithuanian Commonwealth considered by some as the traitor , died here . Ultimately , the castle was captured on January 27 , 1657 . In the following years the castle and surrounding lands were donated to Stefan Czarniecki in reward for his contribution in the war . The new owner rebuilt the castle after 1698 . In November 1705 the meeting between the king Augustus II the Strong and Peter the Great took place here . During this meeting the Order of White Eagle was established by the King of Poland . In 1734 the castle was destroyed by fire . Since that time , no inhabited building began to fall into disrepair . In 1771 remains of the castle were destroyed by flood and in 1914 , during World War I , the material from the remaining walls was used by the German soldiers to build roads . Based on the preserved plans of the fortress , found in the archives in Saint Petersburg , the residential part of the castle has been restored ( west wing in the style of late Gothic ) . The original castle was built on a plan of a trapezoid with a courtyard and four cylindrical towers at the corners . The complex was surrounded with fortifications - curtains combined four terrestrial inner bastions . Treasury . In about 1565 the king Sigismund Augustus installed at the castle his private treasury and a collection of books , initially stored at the Vilnius Castle . Sigismund Augustus was a passionate collector of jewels . According to nuncio Bernardo Bongiovanni ' s relation , his collection was allocated in 16 chests . Among the precious items in his possession was Charles V ' s ruby of 80 000 scudo s ' worth , as well as the Emperor ' s diamond medal with Habsburgs Eagle on one side and two columns with a sign " Plus Ultra " on the other side . He had also a sultan ' s sword of 16 000 ducats ' worth , 30 precious horse trappings and 20 different private - use armour s . The papal nuncio wrote in his diary " I also saw twenty suits of royal armour of which four were of most wondrous workmanship , namely with a beautiful sculpture and figures set with silver [ . . . ] It cost six thousand scudos " . The king ' s possession included a rich collection of tapestries ( 360 pieces ) , commissioned by him in Brussels in the years 1550 - 1560 , which decorated the castle ' s walls . The king ' s treasures were scattered after his death .