Kantakouzinos participated in the capture of Monemvasia and the Siege of Tripolitsa, but in 1822 he fell out with Dimitrios Ypsilantis and joined the camp of his rival, the Phanariote Alexandros Mavrokordatos. He later left Greece and settled in Dresden. He returned to Greece in 1829, after Count Ioannis Kapodistrias became Governor of Greece. As Greek independence became internationally recognized, he bought up the estates ("çifliks") of several Ottoman grandees in Attica, most notably the "mufti" of Athens and Omer Pasha of Karystos, from whom he purchased Tatoi (the future summer residence of the Greek royal family).