At the end of the 15th and beginning of the 16th centuries, Pata was a town-like community, a market-place and trading-centre for the people of Stranda. The commercial centre was established during the second half of the 15th century by the owner of Strömsrum, Sten Sture the Elder. Sten Sture saw an opportunity to make money from the district´s trade.
A number of merchants and craftsmen settled in Pata. The merchants loaded the ships with pieces of wood for barrel-making, rope, cords, tar, butter, fur and fish. One traded with Kalmar, Stockholm, Söderköping and Visby in Sweden as well as with some of the towns in north Germany. One imported salt, cloth, grain and maybe wine and beer, too.
Amongst the craftsmen, we know of a stone-mason, a tailor and of a head cloth-cutter, who dealt in cloth.
Normally, Pata had 75 to 100 inhabitants. On market-days, there would be many hundreds more.
A chapel was erected at Pata to provide the people with spiritual welfare. In the chapel, sermons were held, particularly so when there was a large fair. At archaeological digs, one has found, amongst other things, coins and the tongue of the important prim bell, which was used when the priest blessed the bread and wine at Holy Communion.
At the mouth of the Alsterå River, there were two guarded fortifications which protected the trading-place. Twice, there were fierce battles between the Swedes and the Danes at Pata. The Danes won on both occasions. In 1506, the Danish commander Jens Holgersen Ulfstand burned down both Pata and Strömsrum. In 1520, Danish troops led by Sören Norrby fought a group of rebellious peasants from the region.