St Michael Yaroslavich was the Prince of Tver in Volodymyr and later became the Grand Duke of Volodymyr. "Mykulyn" was an area of Kyivan Rus'-Ukraine that formed part of his original Principality.

St Michael was a holy prince of the ancient Ukrainian lineage that dated back to St Yaroslav the Wise (recently glorified a Saint in Ukraine) and St Volodymyr the Great. He was also related to a number of other saintly Princes of Kyivan Rus'.

Prince Michael was noted for his deep religious devotion and his great support for the Church and her missionaries.

His wife, Anna of Kashin, is also a Saint, but with a controversial background. After her first glorification as a Saint when her Ark or coffin was recovered, it was found that her right hand was in the shape of the two-fingered Sign of the Cross (index and middle fingers extended, last three fingers grouped together). As a result, her cult was "shut down" by the Russian church authorities, since they didn't want to give any support to the Old Believers who crossed themselves this way and whom the Tsars were persecuting for political reasons. She was later exonerated and canonized a second time.

Your surname would indicate the descent of your family from the area that was formerly ruled by St Michael of Tver.

You can take pride in the knowledge that Sts. Michael and Anna of Tver are your family patron saints! They are both depicted in the "All Saints of Rus'" Icon published by Jordanville Monastery in New York.