Tun daga shekarun 1480, Ava ta fuskanci tawaye na cikin gida da kuma hare-haren waje daga jihohin Shan, kuma ya fara wargajewa.A shekara ta 1510, Taungoo, wanda ke cikin kusurwar kudu maso gabas mai nisa na masarautar Ava, ita ma ta ayyana 'yancin kai.^[39] Lokacin da Ƙungiyar Ƙasar Shan ta ci Ava a cikin 1527, 'yan gudun hijira da yawa sun gudu daga kudu maso gabas zuwa Taungoo, wata karamar masarauta mai zaman lafiya, kuma wadda ke kewaye da manyan masarautu masu adawa.Taungoo, karkashin jagorancin sarki Tabinshwehti mai kishi da mataimakinsa janar Bayinnaung, zai ci gaba da hada kananan masarautun da suka wanzu tun bayan faduwar daular Maguzawa, kuma ta sami daula mafi girma a tarihin kudu maso gabashin Asiya.Da farko, masarauta ta farko ta ci Hanthawaddy mafi ƙarfi a cikin Yaƙin Taungoo – Hanthawaddy (1534–41).Taungoo ya koma babban birnin kasar zuwa Bago da aka kwace a shekara ta 1539. Taungoo ya fadada ikonsa zuwa Pagan a shekara ta 1544 amma ya kasa cinye Arakan a 1545-47 da Siam a 1547-49.Magajin Tabinshwehti Bayinnaung ya ci gaba da manufofin fadadawa, inda ya ci Ava a 1555, Jihohin Nearer/Cis-Salween Shan (1557), Lan Na (1558), Manipur (1560), Farther/Trans-Salween Shan Jihohin (1562-63), da Siam (1564, 1569), da Lan Xang (1565-74), kuma ya kawo yawancin yammaci da tsakiyar yankin kudu maso gabashin Asiya a ƙarƙashin mulkinsa.Bayinnaung ya kafa tsarin gudanarwa mai dorewa wanda ya rage ikon sarakunan Shan gado, kuma ya kawo tsarin kwastam na Shan daidai da ka'idodin ƙasa.^[40] Amma ba zai iya yin wani ingantaccen tsarin gudanarwa a ko'ina a cikin daularsa mai nisa ba.Daularsa ta kasance sako-sako da tarin tsoffin masarautu, wadanda sarakunansu suka kasance masu aminci gare shi, ba masarautar Taungoo ba.Masarautar da ta wuce gona da iri, wadda abokan huldar abokantaka da abokan ciniki suka hade, ta ragu jim kadan bayan mutuwarsa a shekara ta 1581. Siam ya balle a shekara ta 1584 kuma ya tafi yaki da Burma har zuwa shekara ta 1605. A shekara ta 1597, masarautar ta yi hasarar dukiyoyinta, ciki har da Taungoo. gidan kakanni na daular.A cikin 1599, sojojin Arakan da ke taimaka wa sojojin haya na Portugal, tare da haɗin gwiwa da sojojin Taungoo masu tawaye, sun kori Pegu.Kasar ta fada cikin rudani, inda kowane yanki ke ikirarin sarki.Dan kasar Portugal dan haya Filipe de Brito e Nicote da gaggawa ya yi tawaye ga ubangidansa na Arakan, kuma ya kafa mulkin Burtugal mai goyon bayan Goa a Thanlyin a 1603.Duk da kasancewa lokacin tashin hankali ga Myanmar, fadada Taungoo ya ƙara yawan isa ga al'umma.Sabbin attajirai daga Myanmar sun yi ciniki har zuwa Rajahnate na Cebu a Philippines inda suka sayar da Sugar Burmese (śarkarā) don zinare na Cebuano.^[41] Filipinos kuma suna da al'ummomin 'yan kasuwa a Myanmar, masanin tarihi William Henry Scott, yana ambaton rubutun Portuguese Summa Orientalis, ya lura cewa Mottama a Burma (Myanmar) yana da manyan 'yan kasuwa daga Mindanao, Philippines.^[42] Lucoes, abokin hamayya ga sauran rukunin Filipino, Mindanaoans, waɗanda a maimakon haka suka fito daga tsibirin Luzon, an kuma ɗauki hayar su a matsayin sojan haya da sojoji na Siam (Thailand) da Burma (Myanmar), a cikin Burma-Siamese. Yaƙe-yaƙe, al'amari iri ɗaya da na Portuguese, waɗanda su ma 'yan amshin shata ne ga ɓangarorin biyu.^[43]