The English forms Swan and Swayne are witnessed in 1379 in the relational bynames Swansoñ (WRYPT1 p. 162) and Swaynessoñ (WRYPT1 p. 300).

Denmark

Danish

● 1581 Suend KD-1 no. 362, Suennd ibid. no. 362, Suenndt ibid. no. 362

England

Latin

● c1145x1159 Swani (gen) EYC-3 1666, Swano (dat) ibid. 1666; 1185x1186 Suein (dat) PR-XXXVI p. 11, Sueino (abl) ibid. p. 5; 1189 Suanus (nom) GASurv p. 173, Suein (nom) ibid. p. 159, Sueinus (nom) ibid. p. 161; 1222 Sweino (nom) StPaulDom p. 81, Sweno (nom) ibid. p. 61, sueni (gen) ibid. p. 20; 1279–80 Swayn (gen) WaHR-SK p. 56

Ireland

Latin

● fin12thC Swein (nom) MunDocIr III, p. 11

Scotland

Latin

● c1100 Swein (abl) ESC XX

Sweden

Latin

● 1350 Suenoni (dat) SDHK no. 6060, Suens (gen) ibid. no. 6059, Swenoni (dat) ibid. no. 6060; 1383 Sweno (nom) SRA-vol2 no. 1901; 1411 Suenonis (gen) SDHK no. 17654, Sweno (nom) ibid. no. 17654

Old Swedish

● 1359 Swen (nom) SDHK no. 7548; 1377 Swen (nom) ibid. no. 11085; 1379 Swens (gen) ibid. no. 11542; 1383 Sweens (gen) SRA-vol2 no. 1940, Swen (nom) ibid. no. 1900; 1403 Swen (nom) SDHK no. 16167; 1408 Swens (gen) ibid. no. 17116; 1409 Swen (nom) ibid. no. 17337, Swens (gen) ibid. no. 17269; 1410 Swen (nom) ibid. no. 17485; 1411 Swen (nom) ibid. no. 17663, Swens (gen) ibid. no. 17627; 1414 Swen (nom) ibid. no. 18236; 1420 Svens (gen) ibid. no. 19436; 1518 Suen (nom) HGS p. 154; 1519 Suen (nom) ibid. p. 154; 1520 Suen (nom) ibid. p. 154

Early Modern Swedish

● 1533 Swen (nom) HGS p. 156; 1535 Swen (nom) ibid. p. 156, Swens (gen) ibid. p. 156; 1541 Swen (nom) ibid. p. 159