The Bjälbo Runestones are three Viking Age memorial runestones, one of which has been lost, located at Bjälbo, which is a village in Mjölby Municipality, Östergötland, Sweden. One of the inscriptions provides evidence of the existence of guilds in Sweden during this period.Ög 64Östergötland Runic Inscription 64 or Ög 64 is the Rundata designation for a granite runestone that is 3.2 meters in height and which was originally found in the wall of the Bjälbo church. Before the historic significance of runestones was understood, they were often re-used as materials in the construction of roads, bridges, and buildings such as churches. The stone was removed from the wall, repaired, and raised in the churchyard in 1935 along with Ög 66. The inscription consists of runic text in the younger futhark that curves once to make two lines. The inscription is classified as being carved in runestone style RAK, which is the classifiecation for runic text bands that have straight ends without any attached serpent or beast heads. There is nothing in the text or design of the inscription that identifies it as being a Christian memorial. The inscription is signed by a runemaster named Lófi. No other surviving runestones have his signature.The runic text states that the stone was raised as a memorial to a man named Greipr by members of a Viking Age guild, who do not name themselves individually unless the runemaster Lofi was also a member of the guild. Ög 64 is one of four runestones that mention guilds in Viking Age Sweden, the others being U 379 in Kyrkogården, U 391 in Prästgatan, and Ög MÖLM1960;230 in Törnevalla. These stones and others discussing félags are evidence of the trading activities during this period of Scandinavian history. The guild-members refer to themselves as drængiaʀ, translated as "valiant men." Drengr is normally a title associated with warriors, but on the runestone Ög MÖLM1960;230 it was used as the name of another guild-member, suggesting that the term drengr was also used among merchants.