He was the great-grandson of King Sahle Selassie of Shewa and his wife Queen Bezabish Dejene of Gojjam through his grandfather, Dejazmatch Mekuria Tesfaye of Gerim Gabriel, a first cousin of Emperor Menelik II of Ethiopia.
He sponsored several Ethiopians for higher education including four artists whom he sent to France after discovering their skills at the Debre Bizen Monastery during his appointment as Consul General to Eritrea.
Seifu expressed these opinions through his surviving poems he wrote during his imprisonment by the fascists at Asinara Island and later in his life as administrator of the Ethiopian Orthodox Tewahedo Church.
In one of his diaries, he expressed his grief over the knowledge of how Lij Iyasu was treated during his years of captivation and his subsequent elimination after Emperor Haile Selassie's decision to leave the country for exile in Europe.
He blamed some of the Emperor's backward advisers with the exception of Luel Ras Kassa Haile Darge whom, he wrote, was too reverential to decide on the life of Lij Iyasu.
Born Seife Sillasie Mikael in Ankobar, Northern Shewa, was active mainly during Empress Zewditu's reign and the earliest times of Emperor Haile Selassie.His father Ato Mikael, a prominent figure in Emperor Menelik II's court, studied in Germany and was the first Ethiopian to publish a modern Amharic mathematics book for Ethiopian students as well as a medical treatise.
The Dejazmach marched with Emperor Menelik II during the monarch's successful efforts in bringing the southern Ethiopian regions under the central imperial government.
Seifu completed the traditional Ethiopian religious education both in Addis Ababa and Menz at the Gerim Gabriel Church located on his grandfather's estate followed by a few years at his father's trading post in Aden, Yemen where he attended modern school.
He left for France after Lij Iyasu assumed imperial power and gave him permission to continue his education abroad at the Sorbonne University in Paris.
According to his renowned nephew Kebede Michael, besides the assistance of his wealthy father, he used his personal funds to pay for his education after inheriting a large amount of money from his grandfather Dejazmatch Mekuria Tesfaye who made him the sole heir to his estate.
In June 1919, he was among the special commissioners sent to Europe by Empress Zewditu who presented a letter of congratulations to the King and Queen of the United Kingdom for the success of the allied arms.He served as Ethiopia's Minister Plenipotentiary to France and Germany at different times between 1920 and 1927.
In the early 1930s, he traveled to Europe with Blattengeta Heruy to help Ethiopia secure permission to buy arms and strengthen Ethiopian position in the League of Nations.
According to the surviving documents, they bought, imported and sold weapons and ammunition worth millions of Maria Theresa Thalers, a favored currency of that time in the Ethiopian Empire.
He later returned to Ethiopia from Djibouti after a fallout with the emperor due to an overheard conversation with Fitawrari TekleHawariat criticizing Haile Selassie over the death of Lij Eyasu.
He joined the resistance leading a contingent of patriots at Awsa front which was the offshoot of the early struggle of the Black Lions created by educated Ethiopians and disbanded members of the army led by Leul Ras(Prince) Imru.
Due to lack of evidence, the Italians overlooked the allegations against Kebede Michael and the fascist appointed Dejazmatch but put Seifu under house arrest at his estate till the liberation.
After the liberation, Emperor Haile Selassie, disappointed by Seifu's opposition over the highly secret decision to eliminate Lij Iyasu before leaving for exile and the remarks he made to him in Djibouti, ordered him to stay under house arrest for a year while pardoning the known collaborators.
Seifu as a result became an increasingly outspoken critic of Haile Selassie and went as far as aiding the patriot from Gojjam, Belay Zeleke with whom he had contact during the resistance, to escape from prison and furnishing him with funds to stay underground to avoid his inevitable elimination.
Offended, the emperor banished him to his Ambo country house and farm where he died from complications of diabetes and high blood pressure in Addis Ababa shortly after.
His funeral was attended by his lifelong friend The Crown Prince Asfaw Wossen Amha Selassie, Princess Tenagnework and several members of the Imperial family, military leaders and the nobility.
In 1927 he married W/o Zewde Haile, the grand daughter of Aba WoldeHana Gebre, a respected elderly monk whose father was one of Menelik's chiefs by the time he brought the Harar province under his rule and a Shewa family of extremely conservative Orthodox Christian roots.
He married Hakim Workneh Eshete's daughter Sarah Martin at St George Church in June 1934,[6] her father was also at one point the governor of Chercher.
Seifu's father Mikael Birru whom the doctor considered a close friend was one of the people who arranged the marriage between Hakim Workneh Eshete and W/o Qatsala Tullu.
The grandchildren of the influential and much respected Dejazmatch Germame of Menelik's era were perceived as independent thinkers and made to serve as ambassadors to different countries and at posts where they didn't enjoy much influence.
The most senior member of the royalty who was captured after a long patriotic struggle he led under the banner of the "Black Lions" he helped create was Leul Ras Imru Haile Selassie, the Emperor's cousin.
His business that supplied gold to the National Bank of Ethiopia and precious stones to the European fashion industry from his offices in Rome and Los Angeles ceased operations due to mismanagement by the government and in some cases, because of the protest from his American and Italian partners who cancelled the contracts over the illegal imprisonment of Lij Kifle.