Who said "Gratitude is the soil in which happiness grows."?

This quote is attributed to Diocletian.

Gratitude is the soil in which happiness grows. - Diocletian

"Gratitude is the soil in which happiness grows."

Diocletian Gratitude

Emperor Ancient Rome 245–316

"A leader who does not consult is a tyrant in waiting."

"The greatest power lies not in conquest, but in knowing when to lay down the sword."

"To govern well, one must first govern oneself."

"Patience is the virtue of those who understand the weight of empire."

"Gratitude makes life richer."

"A grateful heart is a happy heart."

"Respect those who came before us."

"Life's greatest treasures are the people we love"