Events explained by Stefan Andreescu in his book, Vlad Tepes (Dracula) between legend and historical facts, 1976:
April 8, 1437: The dragon emblem appeared on Vlad Dracul’s seal (Vlad the Impaler’s father).
April 17, 1443: A document clearly indicated Basarab II’s paternal ancestry as “Bazarab, filius condam Daan wayvode”.
April 11, 1453: Vladislav II requested “some weapons” to be secretly sent to Târgovişte, which Iancu of Hunedoara wanted to reach Chilia.
April 1454 (Spring): The armistice between Turkey and Hungary, active since 1451, expired.
April 13, 1454: King Ladislau V Postumus, from Prague, ordered Iancu of Hunedoara to support the fortification of Sibiu due to the danger of Turkish invasion.
April-May 1454: Representatives of Christian powers were convened at Regensburg for a crusade against the Turks.
April 6, 1456: King Ladislau V Postumus, from Buda, asked the Saxons to defend the borders of Transylvania from Vladislav II.
April 7, 1456: Iancu of Hunedoara, also from Buda, asked the Braşovians to allow the export of weapons to the Făgăraş fortress.
April 12, 1457: Ştefan cel Mare (Stephen the Great of Moldova, Vlad the Imapler’s cousin), with a small army of Wallachians, defeated Petru Aron near Dolheşti and began his reign in Moldova.
April 15, 1456: The date of the last preserved chrysobull (official document) from Vladislav II (Voyvode of Vallachia), issued in Târgovişte.
April 16, 1457: Vlad the Impaler was in Târgovişte, confirming a village to the Cozia monastery and listing the members of his princely council.
April 1457 (late) or May 1457: Vlad Ţepeş’s army entered southern Transylvania, attacking and burning the villages of Caşolţ, Hosman, and Satul Nou.
April 1459: Ştefan cel Mare adopted a new political orientation by making peace with Poland.
April 5, 1460: Vlad teh Imapelr, from Târgovişte informed the Braşovians of the confiscation of Wallachian merchants’ goods in Braşov.
April 22, 1460: It was known in Pesta that Dan, pretender to the Wallachian throne, had been defeated and executed by Drăculea (Vlad the Impaler).
April 2, 1462: The administration of Caffa wrote to King Casimir of Poland, expressing concern that Ştefan cel Mare’s conflict with Vlad the Impaler might undermine the war against the Sultan.
April 3, 1534: A late chrysobull for Snagov monastery cited a “charter of the great voivode Vlad the Elder who died in the village of Bălteni”.