Costanza della Scala
Costanza della Scala (c. 1263–1306) was the daughter of Alberto I della Scala, lord of Verona. In 1289 she married Obizzo II d'Este, lord of Ferrara. When Obizzo was killed in 1293, probably by his son Azzo VIII, Azzo drove her out of Ferrara in 1294; her father then made war on the Este and defeated them.
In 1299 her brother Cangrande I married her to Guido Bonacolsi, lord of Mantua, sealing the Verona-Mantua alliance. She died at Ferrara in 1306, leaving no sons.