From Longman Dictionary of Contemporary Englishtake on/assume/wear the mantle of somethingtake on/assume/wear the mantle of somethingformalRESPONSIBLE to accept or have an important duty or job It is up to Europe to take on the mantle of leadership in environmental issues. → mantle
Examples from the Corpus
take on/assume/wear the mantle of something• Against all expectations, it has not taken on the mantle of best pupil in the euro class. 