from /r/vexillology
Top comment: Some notes: 1. The Greek flag may have influence from the old Byzantine flag as well, but this link is not as well documented. 2. While the St. Andrew's Saltire was likely introduced to Russia as part of the Union Jack, Russian sources point to St. Andrew's significance in the Russian Church and Navy Churches generally as the reason for the saltire's adoption. 3. After posting this, I realized the demonym of Genoa is Genovese, not Genoese. Sorry. 4. I didn't have the space to include it here, but it is likely that the Russian St. George's Cross (the blue Merchant Jack) also evolved (together with the [Iberian Cross](https://en.wikipedia.org/wiki/Flag_of_Georgia_(country)#/media/File:Kartli_-_drosha_jvari.svg) and [St. Nino's Cross](https://en.wikipedia.org/wiki/Grapevine_cross#/media/File:Grapevine_cross.svg)) into the [Georgian Patriarchate Flag](https://en.wikipedia.org/wiki/Nordic_cross_flag#/media/File:Flag_of_Georgian_Orthodox_Church.svg), creating an interesting if indirect link between the Nordic-looking flags of Finland, the Georgian Orthodox Church, and [Tblisi](https://en.wikipedia.org/wiki/Nordic_cross_flag#/media/File:Flag_of_Tbilisi.svg).
