Dic: at someone's behest

• at someone's command,
• by someone's order,
• at someone's demand,
• at someone's wish,
• by someone's decree,
• at someone's bidding,
• at someone's instruction,
• by someone's mandate,
• at someone's dictate,
• at someone's commandment

........ Collins Essential Thesaurus

behest: n. an authoritative command or request

............ http://www.thefreedictionary.com/behest