[1] He was born in Asunción, and arrived in Buenos Aires as a member of the contingent led by Juan de Garay, for the second foundation of the city in 1580.

[2] The same year of the foundation, Esteban Alegre received 3000 varas of land located on the border of Riachuelo, (La Matanza).

[3] In 1582, he received encomienda of the tribe Alacas (of Guaraní origen) commanded by the cacique Suguna.

[4] Esteban Alegre was married to Isabel de Pantoja,[5] daughter of Isabel Pantoja and Esteban de Vallejos, a Spanish conquistador born in Somorrostro, and who served as Captain and regidor of Santa Fe for 1590s.

[6] His ancestors were Luis Alegre and Dionis de Lys, conquerors from Flanders.