Elena Asenina of Bulgaria

[1][2] She was daughter of Bulgarian Emperor Ivan Asen II and Anna Maria of Hungary.

[3][4] Her maternal grandparents were king Andrew II of Hungary and Gertrude of Merania.

[3] The marriage was apparently very loving, and her husband mourned deeply after her death (from unknown causes) in the spring of 1252.

[2][8] He was devastated by her loss, and only finally ceased the rituals of deep mourning after his father commanded it, requiring his assistance.

[2] Yet, his grief continued, inspiring him to write a series of essays entitled Moral Pieces, that focused on the brevity of life and joy, often revolving around the loss of Elena.