This gold signet ring with the Gyllenhaal coat of arms carved into a carnelian intaglio belongs to Leonard Deane Gyllenhaal of Newtonville, Massachusetts. It was given to him by his father, Leonard Anders, who in turn received it from his father, Leonard Efraim. It has apparently been passed down from father to oldest son since the time of Anders Leonard Gyllenhaal, who emigrated from Sweden to America in 1866. The history of the ring before that time is not known, but it is clear from the goldsmith's marks that it was made in Stockholm in the year 1768. In that year Leonard Gyllenhaal turned sixteen years old, and it is likely that the ring was given to him (or passed down to him) by his father, and then passed down from father to son for a total of seven generations. Each male in the line of descent down to the present owner had Leonard as either his first or middle name, and so it may be that the ring has always belonged to "Leonards."
Other scenarios are possible. The first Leonard's older brother, Johan Abraham, was the oldest child in the family, and he turned eighteen the year that the ring was made. It could have been made for Johan, and then given to Leonard after Johan died in 1788. Furthermore, Leonard's oldest son to live to adulthood was Gustaf Abraham, whose son Carl Leonard lived until 1912. The ring could at some point have been sent by this family overseas to Anders--or even to Anders' oldest son Leonard Efraim--in order to keep it among the descendants of the first Leonard.
The hallmarking of gold, silver and tin was controlled by the state through the "Kontrollverket" in Stockholm, which was set up in 1752. Gold jewelry made after this date was stamped according to an established system of hallmarks, and the marks on the Leonard ring are unmistakable. The "K" on the left fixes the year of manufacture as 1768 (according to this system, the "A" was 1759, "B" was 1760, and so on, until the letters of the alphabet were used up in 1783, which then became "A2"). The mark to the right of the "K" is the three crowns, the symbol of the state of Sweden (stamped upside down by mistake). The stamp to the right of the three crowns is the hallmark of the city of Stockholm, a profile view of Saint Erik (Erik was a legendary medieval king and the patron saint of Stockholm). And the letters "IEB" are the goldsmith's unique stamp, probably the initials of his name. It may be possible to trace these initials and identify the goldsmith.