Jaroslav m. Slavic Jarilo, the name of a god of vegetation, fertility, and springtime, from Proto-Slavic *jaro, *jarъ, *jarь, *jara 'spring (season)' + Slavic sława, slava 'glory, fame'.

Czech Republic

Latin

● 1287 Jaroslaus (nom) RTT-1.1 II; 1291 Jaroslaus (nom) ibid. III; 1345 Jeroslai (gen) CDEM-7.2 605, Jeroslao (abl) ibid. 605, Jeroslaus (nom) ibid. 605; 1348 Jaroslaus (nom) chlumecky 8; 1349 Jarosius (nom) ibid. 128, Jaroslao (dat) ibid. 114, Jaroslaus (nom) ibid. 26, Jarossio (dat) ibid. 76; 1350 Jaroslao (dat) ibid. 168, Jaroslaus (nom) ibid. 175; 1351 Jaroslaus (nom) ibid. 35, Jarossius (nom) ibid. 19; 1353 Jaroslao (abl) ibid. 60, Jaroslaus (nom) ibid. 82; 1355 Jaroslaus (nom) ibid. 65; 1356 Jaroslaus (nom) ibid. 178, p. 29; 1358 Jaroslao (dat) ibid. 465, p. 39, Jaroslaus (nom) ibid. 320, p. 34; 1376 Jaroslaus (nom) LDFPUP1 p. 31, Jheroslaus (nom) ibid. p. 31; 1389 Jaroslaus (nom) ibid. p. 4; 1397 Jarislaus (nom) ibid. p. 5

◑ 1353 Jaros (nom) chlumecky 49, p. 23; 1358 Jarco (nom) ibid. 415, p. 37

Germany

Latin

● 1240 Jerezlaus (nom) UrkMeck1 no. XXVII; 1244 jerezlaus (nom) ibid. no. XXXII; 1252 Jeroslaus (nom) ibid. no. XLIV; 1256 Jeroslaus (nom) ibid. no. XLVIII; 1257 Jerezlaus (nom) ibid. no. L; 1271 Jerezlaus (nom) ibid. no. LXVI

Poland

Latin

◑ 1209 Jarosz (nom) CDT1 II