7 9 , ▁followed ▁by ▁the ▁P ict s ' ▁destruction ▁of ▁the ▁North umb rian ▁army ▁at ▁the ▁Battle ▁of ▁Dun ▁Ne ch tain ▁in ▁ 6 8 5 , ▁reduced ▁North umb rian ▁power ▁and ▁influence . ▁There ▁is ▁evidence ▁of ▁Mer cian ▁activity ▁in ▁the ▁south - east ▁as ▁well . ▁ Æ th el red ▁inv aded ▁Kent ▁in ▁ 6 7 6 , ▁and ▁char ters ▁surv ive ▁in ▁which ▁he ▁confirmed ▁land ▁gr ants ▁made ▁by ▁Sw æ f he ard ▁and ▁O sw ine , ▁k ings ▁of ▁west ▁and ▁east ▁Kent . ▁Another ▁char ter ▁of ▁ Æ th el red ' s , ▁dated ▁between ▁ 6 9 3 ▁and ▁ 7 0 4 , ▁gr ants ▁land ▁to ▁Wald here , ▁the ▁bishop ▁of ▁London . ▁However , ▁ Æ th el red ▁does ▁not ▁appear ▁to ▁have ▁sought ▁expansion ▁further ▁south . ▁The ▁growing ▁strength ▁of ▁the ▁West ▁Sax ons ▁under ▁C æ dw alla ▁and ▁I ne ▁would ▁have ▁limited ▁Mer cian ▁opportun ities ▁in ▁that ▁direction . ▁ ▁The ▁Ang lo - S ax on ▁Chron icle ▁records ▁that ▁in ▁ 7 0 2 ▁Co en red ▁succeeded ▁to ▁the ▁kingdom ▁of ▁the ▁South umb ri ans ▁and ▁that ▁in ▁ 7 0 4 ▁he ▁became ▁king ▁of ▁Mer cia . ▁As ▁the ▁" S outh umb ri ans " ▁were ▁those ▁who ▁lived ▁south ▁of ▁the ▁H umber , ▁Mer cia ' s ▁northern ▁boundary , ▁the ▁two ▁ann