The name Ronni is a diminutive form of the German name Ronald, which itself is derived from the Old Norse name Rögnvaldr. Rögnvaldr is composed of the elements "rögnr" meaning "advice" or "decision," and "valdr" meaning "ruler" or "wielder." The name can be traced back to the 9th century AD and was commonly used by the Vikings and other Scandinavian peoples.

In its early form, Rögnvaldr was a name associated with Norse nobility and rulers. It was borne by several prominent figures in Norse mythology and history, including Rögnvaldr Kali Kolsson, an Earl of Orkney in the 12th century. The name's connotations of wisdom and leadership likely contributed to its popularity among the ruling classes.

As the Vikings explored and settled in various parts of Europe, the name Rögnvaldr spread and evolved into various forms, such as Ronald, Reynold, and Ronni. The diminutive Ronni became popular in certain regions, particularly in Germany and Scandinavia.

One of the earliest recorded instances of the name Ronni dates back to the 13th century, when a Norwegian noblewoman named Ronni Erlingsdatter was mentioned in historical records. In the 15th century, a Danish nobleman named Ronni Vogn served as a courtier to the Danish king.

Throughout history, several notable individuals have borne the name Ronni. One of the most famous was Ronni Pede, a Danish philosopher and theologian who lived from 1571 to 1629. Another was Ronni Aminoff, a Finnish writer and poet who lived from 1900 to 1983. In the realm of sports, Ronni Pettersson was a Swedish ice hockey player who represented Sweden at the 1964 Winter Olympics.

The name Ronni also found its way into the arts, with Ronni Govoni being an Italian painter and sculptor who lived from 1819 to 1873. In the world of music, Ronni Griffiths was a Welsh singer and actress who performed in the early 20th century.

While the name Ronni has its roots in Old Norse and Scandinavian cultures, it has transcended its origins and been adopted in various parts of the world, particularly in Europe and North America. Its enduring popularity can be attributed to its connection to wisdom, leadership, and a rich historical legacy.