It's often forgotten that Portugal once possessed the world's third largest empire, and had a colonial presence in east and west Africa for over 500 years. Indeed so well-established were the Portuguese in Guinea-Bissau, Angola and Mozambique that they thought they were immune to the 'winds of change' that swept the British, French and Belgians out of Africa after WW2. They were shaken out of this complacency by the emergence of liberation movements in all three countries in the early 1960s, and soon found themselves bogged down in endless, unpopular guerilla wars on three fronts. They could contain these militarily (at the crippling cost of 40% of Portugal's GDP) but, like the French in Algeria, could offer no political solutions, and eventually it fell to the war-weary army to break the logjam by toppling the intransigent Salazar regime in Portugal itself in 1974. Sadly the former colonies' woes didn't end with independence: the abrupt transition led to power struggles, which in Angola in particular, lasted for decades and became an archetypal Cold War 'proxy war'.
This invaluable Osprey volume is the only widely-available English work on the subject and takes the usual Men-at-Arms format of a general political/historical overview, followed by well-illustrated features on the Portuguese regular forces and the various guerilla factions who opposed them, rounded off with Ron Volstad's customarily excellent colour uniform plates.
I was hoping to learn a little more about the wars that many of my family were conscripted into but found this book to be very slim on political and historical details. The authors seemed far more obsessed with uniforms, insignia and weapons than the actual wars themselves. From that respect I found it rather disappointing. It will give you an overview of the major players, but not much depth.