1970 AD., Sao Tome and Príncipe, Portuguese colony, 500th anniversary of discovery commemorative, Lisbon mint, 50 Escudos, KM 21.

São Tomé and Príncipe, Portuguese colony, 500th anniversary of discovery commemorative, engravers: Américo (autor) Rosa (escultor), Lisbon mint, 1970 AD.,
50 Escudos (ø 34 mm / 18,12 g), 0.650 silver, 18,00 g theor. mint weight, mintage 150.200 , axis coin alignment ↑↓ (180°), reeded edge,
Obv.: S. Tomé e - Príncipe / 1470 – 1970 / V Centenário / AMERICO – ROSA , two escutcheons on a wind-flower (sun like) above 6 waves between dates and small engraver´s names 1470 / AMERICO (left) and 1970 / ROSA (right) - ao centro, lado a lado, os brasões das cidades de S. Tomé e Santo António sobrepostos a uma rosa-dos-ventos, cujo ponto norte é representado por uma flor-de-lis, tendo por baixo uma faixa de ondas representando o mar, e na orla, as legendas “S. Tomé e Príncipe – V Centenário” e as datas “1470-1970”.
Rev.: Republica Portuguesa / 50 $ 00 , 5 escutcheons from coat of arms Portugal on the Cross of Christ in front of a circle with 4 loops - ao centro uma cruz de Cristo e as cinco quinas sobrepostas, e na orla, a legenda “República Portuguesa” e o valor “50$00”.
KM 21 ; Alberto Gomes 2006 no. ST.26.01.A .

Year / Mintage
1970 150.000
1970 200 matte proof ; rare ; struck on private contract
1970 unknown mintage Prova (Pr24)

The islands of São Tomé and Príncipe were uninhabited when the Portuguese arrived sometime around 1470. The islands were discovered by João de Santarém and Pêro Escobar. Portuguese navigators explored the islands and decided that they would be good locations for bases to trade with the mainland.
The dates of discovery are sometimes given as 21 December (St Thomas's Day) 1471, for São Tomé; and 17 January (St Antony's Day) 1472, for Príncipe, though other sources cite different years around that time. Príncipe was initially named Santo Antão ("Saint Anthony"), changing its name in 1502 to Ilha do Príncipe ("Prince's Island"), in reference to the Prince of Portugal to whom duties on the island's sugar crop were paid.
The first successful settlement of São Tomé was established in 1493 by Álvaro Caminha, who received the land as a grant from the crown. Príncipe was settled in 1500 under a similar arrangement. Cycles of social unrest and economic instability throughout the 19th and 20th centuries culminated in peaceful independence in 1975.

More on https://en.wikipedia.org/wiki/São_Tomé_and_Príncipe