As soon as Tadakuni, who sought further promotions beyond sojaban, recognized that the Karatsu Domain, which was assigned to defend Nagasaki, impeded such promotions, he, against his vassals' advice, requested bakufu to change his domain from the Karatsu Domain with 253,000 koku (70,334 cubic meters) to the Hamamatsu Domain with 153,000 koku (42,534 cubic meters), and finally realized it in September, 1817.
忠邦は奏者番以上の昇格を望んだが、唐津藩が長崎警備の任務を負うことから昇格に障害が生じると知るや、家臣の諫言を押しきって文化14年（1817年）9月、実封25万3000石の唐津から実封15万3000石の浜松藩への転封を自ら願い出て実現させた。