Swami Mudaliyandan (alt Muthaliandan, Muthaliyandan) was a relative, disciple and associate of Shri Ramanuja, the codifier of the philosophy of Shrivaishnavism.
Swami Mudaliyandan was born in 1027 CE at Pachhai Vaarana Perumal Sannidhi (referred to as “NazarethPettai” today) in Thondai mandalam, in the state of Tamil Nadu in South India. His parents were Vaadhoola Kula Thilaka Shri Anantha Naarayana Dikshithar and Nachiyaramman (Shri Ramanuja's sister). Daasarathi, as he was named, was Ramanuja's Priya Bhagineya in the parlance of the age. Born to his service, and known as "Yathiraaja Paaduka", he enjoyed a special relationship with Emberummanaar (Ramanuja) all his life.
Having begun his learning with his father, Daasarathi would go on to become, with Koorathaazhvaan, a pillar of support to Emberumaanar, acclaimed by him as being identical to his thridandam – his staff off office as a sanyasi. However, Emberumaanar kept him busy in many ways, as he was a capable executive and administrator. He was later to be known as "Shriranganaatha Divyaalaya Nirvahana Dhurandhara" – the genius who organized, under Emberumanaars tutelage, the administration of the Shri Ranganathaswamy Temple.
As he ruled the Temple staff like Senai Muthaliyaar (Shri Vishvaksena), he was given the name Muthali-Aandaan. He is mentioned in the Koyil Ozhugu, the chronicle of Shri Ranganathaswamy Temple, in glowing terms: "muthaliyaandaanum kurattilirunthu koyil kariyaththaiyum ulle karuvulaka vaasalileyirunthu thirumeni upachaaraththayum, sannathiyile irunthu thiruppavala upchaarangalayum udayavar niyamanappadi aaraaynthu kondu anaiththazhagum kandarula pannik-kondirunthaar". (Roughly translated as: And Muthaliyandan administered the following, according to Ramanuja's orders, the many works of the Temple, the services to the Lord, and the works of the Shrine.)
Shri Muthaliyaandaan is most well known for his lapidary saying, here given in transliterated manipraavaalam: "oru malaiyil ninru, oru malaiyil thaavum simha shareeraththil janthukkal pole bhaashyakaarar samsaaralanganam panna avarodundaana kudalthudakkaale naam udhdheerdaraavuthomenru muthaliyaandaruli-ch-cheytha paasuram". This is roughly translatable as follows: When a lion leaps from a mountain to another, all the creatures that live on his body go with him. Even so, when Udayavar transcended this world, all of us who are associated with him benefit from this as well.
His descendants are now among the Acharyas of the Shri Vaishnava tradition, and carry the title of Mudaliyandan Swami.
Source : http://en.wikipedia.org/wiki/Mudaliyandan